1756-pm004_-en-p

Programming ManualLogix5000 Controllers I/O and Tag Data Catalog Numbers 1756 ControlLogix, 1756 GuardLogix, 1768 Compact GuardLogix, 1769 CompactLogix, 1789 SoftLogix, PowerFlex with DriveLogix Important User Information Solid-state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls (publication SGI-1.1 available from your local Rockwell Automation sales office or online at http://www.rockwellautomation.com/literature/) describes some important differences between solid-state equipment and hard-wired electromechanical devices. Because of this difference, and also because of the wide variety of uses for solid-state equipment, all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable. In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment. The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for actual use based on the examples and diagrams. No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software described in this manual. Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is prohibited. Throughout this manual, when necessary, we use notes to make you aware of safety considerations. WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which may lead to personal injury or death, property damage, or economic loss. ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage may be present. BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach dangerous temperatures. IMPORTANT Identifies information that is critical for successful application and understanding of the product. Allen-Bradley, Rockwell Software, Rockwell Automation, and TechConnect are trademarks of Rockwell Automation, Inc. Trademarks not belonging to Rockwell Automation are property of their respective companies.2012 Summary of Changes This manual contains new and updated information. IMPORTANT RSLogix 5000 programming software is now known as Studio 5000TM Logix Designer application, a component of the Studio 5000 Engineering and Design Environment. The following controllers are no longer supported in Logix Designer application, version 21. Catalog Number 1756-L61 1756-L61S 1756-L62 1756-L62S 1756-L63 1756-L63S 1756-L64 1756-L65 1768-L43 1768-L43S 1768-L45 1768-L45S 1769-L23E-QBF1 1769-L23E-QBFC1 1769-L23-QBFC1 1769-L31 1769-L32C 1769-L32E 1769-L35CR 1769-L35E Description ControlLogix 5561 Controller ControlLogix 5561S Controller ControlLogix 5562 Controller ControlLogix 5562S Controller ControlLogix 5563 Controller ControlLogix 5563S Controller ControlLogix 5564 Controller ControlLogix 5565 Controller CompactLogix 5343 Controller CompactLogix 5343S Controller CompactLogix 5345 Controller CompactLogix 5345S Controller CompactLogix 5323E-QB1 Controller CompactLogix 5323E-QBFC1 Controller CompactLogix 5323-QBFC1 Controller CompactLogix 5331 Controller CompactLogix 5332C Controller CompactLogix 5332E Controller CompactLogix 5335CR Controller CompactLogix 5335E Controller Changes throughout this revision are marked by change bars, as shown in the margin of this page. This table contains the changes made to this revision. Topic Extended Properties Using extended properties in logic Adding Extended Properties to a Tag Min and Max for DINT, INT, LINT, SINT, and REAL Data Types Adding Extended Properties to a User-Defined Data Type Paste a Pass-Through Description Project Documentation Page 25 30 33 34 43 46 55 Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 1 Summary of Changes Notes: 2 Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Guidelines for User-defined Data Types . . . . . . . . . . . . Configuring an Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tag Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .September 2012 3 . . . . 7 Requested Packet Interval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display Alias Information . . . . . . . . . . Array Subscript Out of Range . . . . . . . . . . . . . . . . 20 Chapter 2 Organizing Tags Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Assign an Alias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Address Tag Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alias Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Project Documentation . 23 24 25 27 29 33 33 35 38 39 40 41 43 44 45 46 47 48 49 50 51 52 54 55 55 Rockwell Automation Publication 1756-PM004D-EN-P . . . . . . . . . . . . . . . . . . 9 Ownership. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Communication Format . . . . . . . . . . . . . Describing a User-defined Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Table of Contents Preface Studio 5000 Engineering and Design Environment and Logix Designer Application . . . . . . . . . Assign an Indirect Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Compatible Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Paste a Pass-Through Description. 5 Chapter 1 Communicate with I/O Modules Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . Activate Pass-Through and Append Descriptions . . . . . . . . . . . Create an Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Direct or Rack-Optimized Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Create a Tag . . . . . . . . . . . . . . . . . . 5 Purpose of This Manual . . . . . . . . . . . . . . . . . . . . 12 Exact Match . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adding Extended Properties to a User-Defined Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Creating a User-defined Data Type . . . . . . . . . . Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Electronic Keying . . . . . . . . . 14 Address I/O Data . . . . . . . . . . . . . . . . . . . . . . Adding Extended Properties to a Tag. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Expressions . . . . . 19 Buffer I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tag Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Creating a User-defined Data Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Guidelines for Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 External Access Options. . . . . . . . . . . . . . . . . 65 Configure External Access. . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Add-On Instructions Constant Value Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Precautions . . . . . Force an Input Value . . . . . . . . . . . . . . . . . . . . . When to Use I/O Force. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 User-defined Type Considerations . . . 66 Configure External Access in the New Tag Dialog Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Force an Output Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Constant Checkbox Availability . . . . . . . . . . . . . . . . . . . . 73 Add-On Instructions External Access Considerations . . . . . . . . . . . . . . . . . . . . . .September 2012 . . . . . . . . . . . . . . 73 Tag Mapping Considerations. . . . . . . . . . . . . . . . . . . . . 67 Set Up External Access in the Tag Properties Dialog Box . . . . . . . . . . Disable All I/O Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 External Access Availability . . . . . . . . . . . . . . . .Table of Contents Chapter 3 Force I/O Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Add an I/O Force . . . . . . . . . . Remove or Disable Forces . . . . . . . . . . . . . . . . . . . . . . . 78 Set Up a Constant in the New Tag Dialog Box . . . . . . . . . Disable or Remove a Force. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Remove an Individual Force . . . . . . . . . . Enable Forces. . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Designate a Constant in the Tag Editor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Remove All I/O Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 View and Select External Access Status on the Tag Editor Window 70 ‘Go To’ Search Menu . . . . . . . . . . . . . . . . . . . . . . Check Force Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Configure Constant Tags . . . . . . . . . . . GSV Instruction . . 65 External Access. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Configure a Constant in the Tag Properties Dialog Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FORCE Status Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Imported Tag Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Constant Value Tags. . . . . . . . 57 57 57 58 58 59 59 60 61 61 61 62 62 63 63 Chapter 4 Data Access Control Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Index 4 Rockwell Automation Publication 1756-PM004D-EN-P . . . . . . . . . . . . . . . . . . . . . . . . . . batch. motion. safety. publication 1756-PM001. and drive-based solutions. This manual is one of a set of related manuals that show common procedures for programming and operating Logix5000 controllers.September 2012 5 . Rockwell Automation Publication 1756-PM004D-EN-P . • SoftLogix5800 controllers. For a complete list of common procedures manuals. refer to the Logix5000 Controllers Common Procedures Programming Manual. such as: • CompactLogix and Compact GuardLogix controllers • ControlLogix and GuardLogix controllers • DriveLogix controllers. Purpose of This Manual This manual shows how to access I/O and tag data in Logix5000 controllers. The Logix Designer application is the rebranding of RSLogix™ 5000 software and will continue to be the product to program Logix5000™ controllers for discrete. The term Logix5000 controller refers to any controller that is based on the Logix5000 operating system. The first element in the Studio 5000 environment is the Logix Designer application. The Studio 5000 environment is the foundation for the future of Rockwell Automation® engineering design tools and capabilities. • FlexLogix controllers.Preface Studio 5000 Engineering and Design Environment and Logix Designer Application The Studio 5000™ Engineering and Design Environment combines engineering and design elements into a common environment. process. It is the one place for design engineers to develop all the elements of their control system. Preface Notes: 6 Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 . Add I/O modules here. you add the module to the I/O Configuration folder of the controller. these are some common options that you typically configure: · Requested Packet Interval · Communication Format · Electronic Keying Rockwell Automation Publication 1756-PM004D-EN-P . While the configuration options vary from module to module. you also define a specific configuration for the module.Chapter 1 Communicate with I/O Modules Introduction To communicate with an I/O module in your system.September 2012 7 . When you add the module. The values update asynchronous to the execution of logic. · To prevent an input value from changing during a scan. Requested packet interval (RPI) In Logix5000 controllers. the controller updates a value independently from the execution of logic. but the control system guarantees that the data transfers at least as often as the RPI. PanelView terminal. · Logic within any task can modify controller-scoped data. The range is 0. The timing of this slot may not coincide with the exact value of the RPI. · Programs within a task access input and output data directly from controller-scoped memory. · An input value referenced at the beginning of a task’s execution can be different when referenced later. Many I/O modules support different formats. Communication Format The communication format that you choose determines the data structure for the tags that are associated with the module. you configure an RPI in milliseconds (ms).2 ms (200 microseconds)…750 ms. Each format uses a different data structure. copy the value to another tag and use the data from there (buffer the values).September 2012 . The following types of communication use connections: ·I/O modules ·produced and consumed tags ·certain types of Message (MSG) instructions (not all types use a connection) The RPI specifies the period at which data updates over a connection. You can duplicate or buffer data at the beginning of the scan to provide reference values for your logic. A communication link between two devices. Connections are allocations of resources that provide more reliable communications between devices than unconnected messages. The communication format that you choose also determines: · Direct or Rack-Optimized Connection. ·Typically. · Data and I/O values are asynchronous and can change during the course of a task’s execution. At the specified interval. The number of connections that a single controller can have is limited.Chapter 1 Communicate with I/O Modules Requested Packet Interval Term Connection Definition The Logix5000 controller uses connections to transmit I/O data. or another controller. For example. an input module sends data to a controller at the RPI that you assign to the module. ATTENTION: Make sure that data memory contains the appropriate values throughout a task’s execution. 8 Rockwell Automation Publication 1756-PM004D-EN-P . · Ownership. You indirectly determine the number of connections the controller uses by configuring the controller to communicate with other devices in the system. such as between a controller and an I/O module. I/O values update at a period that you configure via the I/O configuration folder of the project. the RPI reserves a slot in the stream of data flowing across the ControlNet network. ·If a ControlNet network connects the devices. sets fault bits in the data area associated with the module. This means that multiple devices can receive the same data at the same time from a single device. A rack-optimized connection consolidates connection usage between the controller and all the digital I/O modules in the chassis (or DIN rail). such as a module fault or the removal of a module while under power. there is one connection for the entire chassis (or DIN rail). Rather than having individual. The controller maintains and monitors the connection with the I/O module. you can select rack-optimized communication. Rack-Optimized Connection Ownership In a Logix5000 system. A direct connection is any connection that does not use the Rack Optimization Comm Format.Communicate with I/O Modules Chapter 1 Direct or Rack-Optimized Connection The Logix5000 controller uses connections to transmit I/O data. Rockwell Automation Publication 1756-PM004D-EN-P . Rack-optimized connection For digital I/O modules. These connections can be direct connections or rack-optimized connections. modules multicast data. direct connections for each I/O module. data transfer link between the controller and an I/O module.September 2012 9 . Any break in the connection. Term Direct connection Definition A direct connection is a real-time. not listen-only) Listen-only Stop communication with the module if it loses communication with the other controller Output module Does not own the module Owns the module There is a noted difference in controlling input modules versus controlling output modules. Listen-only Owner (such as. you have to choose whether to establish an owner or listen-only relationship with the module. Owner controller The controller that creates the primary configuration and communication connection to a module.Choose the Type of Ownership If module is Input module And another controller Does not own the module Owns the module Maintain communication with the module if it loses communication with the other controller And you want to Then use this type of connection Owner (not listen-only) Owner (not listen-only) Use the same configuration as the other owner controller. An owner connection is any connection that does not include Listen-Only in its Comm Format. The owner controller writes configuration data and can establish a connection to the module. 10 Rockwell Automation Publication 1756-PM004D-EN-P .Chapter 1 Communicate with I/O Modules When you choose a communication format.September 2012 . Listen-only Connection Use the following table to choose the type of ownership for a module. A controller using a listen-only connection only monitors the module. Table 1 . Listen-only connection An I/O connection where another controller owns/provides the configuration data for the I/O module. It does not write configuration data and can only maintain a connection to the I/O module when the owner controller is actively controlling the I/O module. September 2012 11 . If all owner controllers break their connections to the input module. other controllers can establish listenonly connections to that module. all controllers with listen-only connections no longer receive multicast data. otherwise. Once an output module has been configured (and owned by one controller). If the owner controller breaks its connection to the output module. other controllers can establish a listen-only connection to that module. the connection attempt is rejected.Communicate with I/O Modules Chapter 1 Table 2 . the connection attempt is rejected. An output module is configured by a controller that establishes a connection as an owner. Once an input module has been configured (and owned by a controller). This configuring controller is the first controller to establish an owner connection. Listen-only Output modules Owner Listen-only Rockwell Automation Publication 1756-PM004D-EN-P . If another controller attempts to establish an owner connection. other controllers can establish owner connections to that module. Only one-owner connection is allowed for an output module. Once an input module has been configured (and owned by a controller).Control Input and Output Modules Controlling Input modules This Ownership Owner Description An input module is configured by a controller that establishes a connection as an owner. all controllers with listen-only connections no longer receive multicast data. These controllers can receive multicast data while another controller owns the module. All other additional owners must have the identical configuration data and identical communications format that the original owner controller has. These controllers can receive multicast data while another controller owns the module. This lets additional owners to continue to receive multicast data if the original owner controller breaks its connection to the module. for example. fewer options are available. generally represented by its catalog number. the user-selected keying option determines if. 1756-IB16I.Chapter 1 Communicate with I/O Modules Electronic Keying The electronic keying feature automatically compares the expected module. A number that represents the functional capabilities and data exchange formats of the module. For some specific module types. although not always. Minor Revisions typically do not impact data compatibility but may indicate performance or behavior improvement. When a Logix5000 controller begins communicating with a module. 12 Rockwell Automation Publication 1756-PM004D-EN-P . Major Revision of the same catalog number and. The specific type of module. Minor Revision You can find revision information on the General tab of a module’s Properties dialog box. a later. or digital I/O. AC drive. possibly. for example. an electronic keying check is performed. Major Revision supports at least all of the data formats supported by an earlier.General Tab IMPORTANT Changing electronic keying selections online may cause the I/O communication connection to the module to be disrupted and may result in a loss of data.September 2012 . Attribute Vendor Product Type Catalog Number Major Revision Description The manufacturer of the module. Typically. this set of keying attributes is considered. ·Exact Match ·Compatible Module ·Disable Keying You must carefully consider the benefits and implications of each keying option when selecting between them. that is lower. You can use electronic keying to help prevent communication to a module that does not match the type and revision expected. For each module in the I/O Configuration tree. A number that indicates the module’s specific firmware revision. The general type of the module. communication adapter. and how. as shown in the Logix Designer I/O Configuration tree. three keying options are available. additional ones. for example. to the physical module before I/O communication begins. that is higher. Typically. Electronic keying is based on a set of attributes unique to each product revision. Rockwell Automation/Allen-Bradley. Figure 1 . 2. and Minor Revision. Exact Match keying prevents I/O communication: The module configuration is for a 1756-IB16D module with module revision 3.1. such as for use in highlyregulated industries. I/O communication is not permitted with the module or with modules connected through it. of the physical module and the module created in the software to match precisely in order to establish communication. Use Exact Match keying when you need the system to verify that the module revisions in use are exactly as specified in the project. EXAMPLE In the following scenario. communication is prevented because the Minor Revision of the module does not match precisely. Rockwell Automation Publication 1756-PM004D-EN-P . If any attribute does not match precisely.Communicate with I/O Modules Chapter 1 Exact Match Exact Match keying requires all keying attributes. as in the case of a communication module. Catalog Number.September 2012 13 . Exact Match keying is also necessary to enable Automatic Firmware Update for the module via the Firmware Supervisor feature from a Logix5000 controller. In this case. that is. Vendor. The physical module is a 1756-IB16D module with module revision 3. Module Configuration Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3 Minor Revision = 1 Communication is prevented Physical Module Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3 Minor Revision = 2 IMPORTANT Changing electronic keying selections online may cause the I/O Communication connection to the module to be disrupted and may result in a loss of data. Major Revision. Product Type. provided that the configured module is one the physical module is capable of emulating. Release notes for individual modules indicate the specific compatibility details. and module types implement the compatibility check differently based on the family capabilities and on prior knowledge of compatible products.Chapter 1 Communicate with I/O Modules Compatible Module Compatible Module indicates that the module determines whether to accept or reject communication. Different module families. the developers cannot know future developments. The exact level of emulation required is product and revision specific. Compatible Module is the default setting. Major Revision. communication adapters. the selection makes it possible to use a replacement that is a different catalog number than the original. revision of the physical module that you believe will be used in the system. lowest. that is higher. we recommend that you configure your module using the earliest. the module developers consider the module’s development history to implement capabilities that emulate those of the previous module. Because of this.September 2012 . When a module is created. Compatible Module allows the physical module to accept the key of the module configured in the software. when a system is configured. you can replace a 1756CNBR module with a 1756-CN2R module. 14 Rockwell Automation Publication 1756-PM004D-EN-P . you can replace a module of a certain Major Revision with one of the same catalog number and the same or later. However. For example. With Compatible Module. that is. In some cases. In this case. Module Configuration Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3 Minor Revision = 3 Communication is prevented Physical Module Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3 Minor Revision = 2 Rockwell Automation Publication 1756-PM004D-EN-P .Communicate with I/O Modules Chapter 1 By doing this. Compatible Module prevents I/O communication: The module configuration is for a 1756-IB16D module with module revision 3.September 2012 15 .3. communication is prevented because the minor revision of the module is lower than expected and may not be compatible with 3. you can avoid the case of a physical module rejecting the keying request because it is an earlier revision than the one configured in the software.3. EXAMPLE In the following scenario.2. The physical module is a 1756-IB16D module with module revision 3. Chapter 1 Communicate with I/O Modules EXAMPLE In the following scenario. communication is allowed because the major revision of the physical module is higher than expected and the module determines that it is compatible with the prior major revision. 16 Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 .2.1. Module Configuration Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 2 Minor Revision = 1 Communication is allowed Physical Module Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16D Major Revision = 3 Minor Revision = 2 IMPORTANT Changing electronic keying selections online may cause the I/O communication connection to the module to be disrupted and may result in a loss of data. The physical module is a 1756-IB16D module with module revision 3. Compatible Module allows I/O communication: The module configuration is for a 1756-IB16D module with module revision 2. In this case. Disable Keying prevents I/O communication: ATTENTION: The module configuration is for a 1756-IA16 digital input module.September 2012 17 . such as data size and format. With Disabled Keying. I/O communication may occur with a module other than the type specified in the I/O Configuration tree with unpredictable results. if used incorrectly. property damage. this option can lead to personal injury or death. Other attributes. you must take full responsibility for understanding whether the module being used can fulfill the functional requirements of the application. or economic loss. We generally do not recommend using Disabled Keying. ATTENTION: Be extremely cautious when using Disabled Keying. EXAMPLE ATTENTION: In the following scenario. In this case. The physical module is a 1756-IF16 analog input module. If you use Disabled Keying. Module Configuration Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IA16 Major Revision = 3 Minor Revision = 1 Communication is prevented Physical Module Vendor = Allen-Bradley Product Type = Analog Input Module Catalog Number = 1756-IF16 Major Revision = 3 Minor Revision = 2 Rockwell Automation Publication 1756-PM004D-EN-P . communication is prevented because the analog module rejects the data formats that the digital module configuration requests.Communicate with I/O Modules Chapter 1 Disabled Keying Disabled Keying indicates the keying attributes are not considered when attempting to communicate with a module. are considered and must be acceptable before I/O communication is established. September 2012 . In this case. communication is allowed because the two digital modules share common data formats. 18 Rockwell Automation Publication 1756-PM004D-EN-P . The physical module is a 1756-IB16 digital input module. Module Configuration Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IA16 Major Revision = 2 Minor Revision = 1 Communication is allowed Physical Module Vendor = Allen-Bradley Product Type = Digital Input Module Catalog Number = 1756-IB16 Major Revision = 3 Minor Revision = 2 IMPORTANT Changing electronic keying selections online may cause the I/O communication connection to the module to be disrupted and may result in a loss of data.Chapter 1 Communicate with I/O Modules EXAMPLE In the following scenario. Disable Keying allows I/O communication: The module configuration is for a 1756-IA16 digital input module. The structure depends on the specific features of the I/O module. ·For a digital module.Communicate with I/O Modules Chapter 1 Address I/O Data I/O information is presented as a set of tags. a Channel member (CH#) usually stores the data for a channel.Bit = Optional Where Location Is Network location LOCAL = same chassis or DIN rail as the controller ADAPTER_NAME = identifies remote communication adapter or bridge module Slot Type Slot number of I/O module in its chassis or DIN rail Type of data I = input O = output C = configuration S = status Member Specific data from the I/O module. ·For an analog module. When you add a module to the I/O Configuration folder… …the software automatically creates controllerscoped tags for the module. SubMember Bit Specific data related to a Member. depends on the size of the I/O module (0…31 for a 32-point module) Rockwell Automation Publication 1756-PM004D-EN-P . An I/O address follows this format: Location :Slot :Type . Specific point on a digital I/O module.SubMember . a Data member usually stores the input or output bit values. · Each tag uses a structure of data. · The name of the tag is based on the location of the I/O module in the system.Member .September 2012 19 . depends on what type of data the module can store. September 2012 .) · To copy an input or output tag to a member of a structure or element of an array. Follow these steps to buffer I/O. (I/O updates asynchronous to the execution of logic. reference the buffer tags. On the rung before the logic for the function. the logic uses a copy of the I/O data. copy the data from the buffer tags to the corresponding output tags. On the rung after the function.Chapter 1 Communicate with I/O Modules Buffer I/O Buffering is a technique that logic does not directly reference or manipulate the tags of real I/O devices. Buffer I/O in the following situations: · To prevent an input or output value from changing during the execution of a program. Instead. 20 Rockwell Automation Publication 1756-PM004D-EN-P . In the logic of the function. copy or move the data from the required input tags to their corresponding buffer tags. 3. 1. 2. 4 drill[1].Data[0]. EXAMPLE Buffer I/O The main routine of the program executes the following subroutines in this sequence. JSR Jump to Subroutine Routine name map_inputs JSR Jump to Subroutine Routine name drill JSR Jump to Subroutine Routine name map_outputs The map_inputs routine copies the values of input devices to their corresponding tags that are used in the drill routine.depth_limit _1791_8AC:I.part_advance / drill[1].home_limit The drill routine executes the logic for the drill machine. drill[1].0 drill[1].1 42369 Rockwell Automation Publication 1756-PM004D-EN-P .retract drill[1].Data[0].0 drill[1].retract _1791_8AC:O.Data[0].0 ONS drill[1].home_limit / drill[1].Data[0]. drill[1]. _1791_8AC:I.depth_limit / drill[1].forward drill[1].retract The map_outputs routine copies the values of output tags in the drill routine to their corresponding output devices.Communicate with I/O Modules Chapter 1 This example copies inputs and outputs to the tags of a structure for a drill machine.September 2012 21 .forward one_shots.forward _1791_8AC:O.depth_limit drill[1]. September 2012 .Chapter 1 Communicate with I/O Modules This example uses the CPS instruction to copy an array of data that represent the input devices of a DeviceNet network. EXAMPLE Buffer I/O Local:0:I.Data[0] Dest input_buffer[0] Length 20 42578 22 Rockwell Automation Publication 1756-PM004D-EN-P . – As the application executes. To synchronize the inputs with the application. – While the CPS instruction copies the data.Data stores the input data for the DeviceNet network that is connected to the 1756-DNB module in slot 0. the CPS instruction copies the input data to input_buffer. no I/O updates can change the data. CPS Synchronous Copy File Source Local:0:I. it uses for its inputs the input data in input_buffer. · In conventional programmable controllers. This lets you: – organize your data to mirror your machinery. Term Tag Definition A text-based name for an area of the controller’s memory where data is stored. The controller uses the tag name internally and does not need to cross-reference a physical address. ·When you create a tag that stores data that requires less than four bytes. ·Tags are the basic mechanism for allocating memory. The tag name itself identifies the data. F8:3. such as N7:8. – Symbols are required to make logic easier to interpret. ·The minimum memory allocation for a tag is four bytes. a physical address identifies each item of data. numeric format that depends on the type of data.Chapter 2 Organizing Tags Introduction With a Logix5000controller. you use a tag (alphanumeric name) to address data (variables). – Addresses follow a fixed. – document (through tag names) your application as you develop it. referencing data from logic. there is no fixed.September 2012 23 . but the data only fills the part it needs. the controller allocates four bytes. Rockwell Automation Publication 1756-PM004D-EN-P . and monitoring data. numeric format. · In Logix5000 controllers. September 2012 . If you want the tag to Store a value or values for use by logic within the project Represent another tag Send data to another controller Receive data from another controller Then choose this type Base Alias Produced Consumed If you plan to use produced or consumed tags. 24 Rockwell Automation Publication 1756-PM004D-EN-P . you must follow additional guidelines as you organize your tags. See the Logix5000 Controllers Produced and Consumed Tags Programming Manual.Chapter 2 Organizing Tags EXAMPLE Tags Analog I/O Device Integer Value Storage Bit Counter Timer Digital I/O Device Tag Type The tag type defines how the tag operates within your project. publication 1756-PM011. and so forth. ·Within a structure. members have a name and data type. floating-point value. such as a bit. Rockwell Automation Publication 1756-PM004D-EN-P . The extended properties include: • Min • Max • Engineering Units • State0 • State1 When these properties are added. Function Blocks. called a user-defined data type. ·You can create your own structures. Extended properties for a tag are added and modified in the Tag Properties pane.Organizing Tags Chapter 2 Data Type Term Data type Structure Definition The data type defines the type of data that a tag stores. A data type that is a combination of other data types. and so forth. For Analog device in floating-point mode Analog device in integer mode (for very fast sample rates) ASCII characters Bit Counter Digital I/O point Floating-point number Integer (whole number) Sequencer Timer Select REAL INT String BOOL COUNTER BOOL REAL DINT CONTROL TIMER Extended Properties You have the option to add extended properties to select tags. ·A Logix5000 controller contains a set of predefined structures (data types) for use with specific instructions such as timers. The following table outlines the most common data types and when to use each. ·A structure is formatted to create a unique data type that matches a specific need. string.September 2012 25 . counters. integer. their values are made available for use by some Rockwell Automation HMIs. ·Like tags. each individual data type is called a member. 768…+32. click the + sign.17549435E-38 (negative values) 0 1.767 -2.September 2012 .647 …-1.40282347E38 (positive values) The COUNTER and TIMER data types are examples of commonly used structures.483.648…+2. the controller allocates four bytes. use the COP instruction. click the – sign. but the data only fills the part it needs.147.147. TIMER Structure Members of running_seconds Data Type Members 42365 To copy data to a structure.483. To expand a structure and display its members. 26 Rockwell Automation Publication 1756-PM004D-EN-P . When you create a tag that stores data that requires less than four bytes. COUNTER Structure To collapse a structure and hide its members.Chapter 2 Organizing Tags The minimum memory allocation for a tag is four bytes. publication 1756-RM003.40282347E38 Not used Not used Not used 16 15 8 7 1 0 0 or 1 -128…+127 -32. Refer to the Logix5000 Controllers General Instructions Reference Manual.17549435E-38 …3. Data type Bits 31 BOOL SINT INT DINT REAL -3. Organizing Tags Chapter 2 Scope When you create a tag. Controller tags (Global data) All programs have access to data that is at the controller scope. ·Routines cannot access data that is at the program scope of another program. For example. Tag_1 Tag_2 Tag_3 Program_A Program tags (Local data) Other routines Main routine Tag_4 Tag_5 Tag_6 Data Program_B Program tags (Local data) Other routines Main routine Tag_4 Tag_5 Tag_6 Data at the program scope is isolated from other programs. There is no need to manage conflicting tag names between programs. Project Controller tags (Global data) I/O data System-shared data Task Program Program tags (Local data) Other routines Main routine A Logix5000 controller lets you divide your application into multiple programs. Rockwell Automation Publication 1756-PM004D-EN-P . you define it as either a controller tag (global data) or a program tag for a specific program (local data). This makes it easier to reuse both code and tag names in multiple programs. both Program_A and Program_B can have a program tag named Tag_4.September 2012 27 . ·You can reuse the tag name of a program-scoped tag in multiple programs. each with its own data. Table 3 .September 2012 .Chapter 2 Organizing Tags Avoid using the same name for both a controller tag and a program tag. Within a program. you cannot reference a controller tag if a tag of the same name exists as a program tag for that program. Certain tags must be controller scope (controller tag).Controller Scope Tags If you want to use the tag In more than one program in the project In a Message (MSG) instruction To produce or consume data In any of the seven AXIS data types To communicate with a PanelView terminal None of the above Program scope (program tags) Controller scope (controller tags) Then assign this scope 28 Rockwell Automation Publication 1756-PM004D-EN-P . use a two-dimensional array to organize the data for a tank farm. use the DINT data type Then assign this scope Controller scope (controller tags) Program scope (program tags) To increase the efficiency of your logic.Guideline Create user-defined data types Use the following guidelines to create tags for a Logix5000 project. including temperatures. Whenever possible. Avoid using the same name for both a controller tag and a program tag. valve positions. use the individual bits of a DINT tag or an array of DINTs. two. This helps reduce the risk of inadvertently changing tags. This makes it more difficult to initialize and clear an array of BOOL data. Use arrays to quickly create a group of similar tags Take advantage of program-scoped tags If you want the tag In more than one program in the project In a Message (MSG) instruction To produce or consume data In any of the seven AXIS data types To communicate with a PanelView terminal None of the above For integers. See “External Access” on page 65. minimize the use of SINT or INT data types. ·reduce the number of tags to browse when configuring HMI. For example. ·A Logix5000 controller typically compares or manipulates values as 32-bit values (DINTs or REALs). you cannot reference a controller tag if a tag of the same name exists as a program tag for that program. ·Arrays let you organize a block of tags that use the same data type and perform a similar function. ·If the destination is a SINT or INT tag. See “Constant Value Tags” on page 77. This keeps related data together and easy to locate. A constant value can be assigned to a tag to prevent the table-backed data from being changed programmatically. ·Typically. use a BOOL array for the bit-level objects of a PanelView screen. use the DINT data type for integers. Certain tags must be controller scope (controller tag).September 2012 29 . This helps: ·reduce the risk of inadvertently changing tags. ·Each individual piece of data (member) gets a descriptive name. define each tag at the program scope (program tags) for a different program. This automatically creates an initial level of documentation for your logic. ·You can use the data type to create multiple tags with the same data layout. pressures. ·The controller typically converts a SINT or INT value to a DINT or REAL value before it uses the value. A user-defined data type provides these advantages: ·One tag contains all the data related to a specific aspect of your system. Then create a tag for each of your tanks based on that data type. Within a program. External access limits the exposure of controller tags by defining a user’s ability to edit tags to Read/Write. use a user-defined data type to store all the parameters for a tank. An array creates multiple instances of a data type under a common tag name. ·Otherwise. This lets you reuse both logic and tag names in multiple programs. Read Only and None.Organizing Tags Chapter 2 Guidelines for Tags Table 4 . Important: Minimize the use of BOOL arrays. regardless of its data type. The location of the element within the array represents the geographic location of the tank. and preset values. or three dimensions to match what the data represents. If you want multiple tags with the same name. Details User-defined data types (structures) let you organize data to match your machine or process. ·The conversion to or from SINTs or INTs occurs automatically with no extra programming. For example. ·You organize the data in one. But it takes extra execution time and memory. Each element of the array represents a single tank.Tag Guidelines Table 5 . Many array instructions do not operate on BOOL arrays. Use most restrictive external access Enable constant attribute for tags that should not be changed by logic Rockwell Automation Publication 1756-PM004D-EN-P . the controller typically converts the value back to a SINT or INT value. mixed case is easier to read. use similar starting characters for tags that you want to keep together. Tag Name North_Tank … … … South_Tank Other tags that start with the letters o. and underscores (_) ·Must start with an alphabetic character or an underscore ·No more than 40 characters ·No consecutive or trailing underscore characters (_) ·Not case sensitive Although tags are not case sensitive (upper case A is the same as lower case a). To make it easier to monitor related tags. numeric characters (0…9). For example: In the Ladder Editor. and so forth. … Using extended properties in logic You can access limit extended properties defined on tags using the . Use mixed case These tags are easier to read Tank_1 Tank1 Than these tags TANK_1 TANK1 tank_1 tank1 Consider the alphabetical order of tags Logix Designer application displays tags of the same scope in alphabetical order. p. q.@Max syntax.Chapter 2 Organizing Tags Table 4 . you cannot write to extended properties values in logic. you can use limit extended properties on an instruction’s source operand.@Min and . the tags may end up separated from each other.September 2012 .Tag Guidelines Table 5 . Tag Name Tank_North Tank_South Otherwise. However. Starting each tag for a tank with ‘Tank’ keeps the tags together.Guideline Limit a tag name to 40 characters Details Here are the rules for a tag name: ·Only alphabetic characters (A-Z or a-z). 30 Rockwell Automation Publication 1756-PM004D-EN-P . Organizing Tags Chapter 2 Table 4 - Tag Guidelines Table 5 - Guideline Using extended properties in logic (continued) Details In the Function Block Editor, you can access extended properties in logic by wiring an Input Reference to a block’s input pins. In the Structured Text Editor, you can access limit extended properties in logic on the right hand side of an assignment operation or in a comparison statement. You can also access limit extended properties in logic when you embed structured text in the Sequential Function Chart Editor. You need to know which tags have limit extended properties associated with them as there is no indication in the Tag Browser that extended properties are defined for a tag. If however, you try to use extended properties that have not been defined for a tag, the editors show a visual indication (that is: a rung error in Ladder Logic, a verification error X in Function Block Diagrams, and the error underlined in Structured Text) and the routine does not verify. ·Restrictions to adding extended properties in logic The following restrictions apply when you use extended properties in logic. · Extended properties must be used as an input operand Extended properties can be used on an instruction as long as the input (source) operand is a non-boolean atomic data type. That is, if an instruction has operands whose data type is non-atomic or BOOL, limit extended properties can not be used. For example, the ALMD instruction in Ladder Logic does not support extended properties because its configurable operands are of type BOOL. In the Ladder Editor, when limit extended properties is used in logic, the value field associated with the source operand is unavailable. You can change the tag's extended properties only in the Tag Properties Pane. · Alias Tags with Extended Properties cannot be accessed in Logic If alias tag extended properties are used in logic, the routine does not verify. Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 31 Chapter 2 Organizing Tags Table 4 - Tag Guidelines Table 5 - Guideline Using extended properties in logic (continued) Details ·Array Tags are constrained A constraint on array tags apply if the array tag uses indirect addressing to access limit extended properties. If an array tag is using indirect addressing to access limit extended properties in logic, the following conditions apply. – If the Array Tag has limit extended properties configured, the extended properties are applied to any array element that does not explicitly have that particular extended property configured. For example, if the MyArray has Max configured to 100, then any element of the array that does not have Max configured inherits the value of 100 when being used in logic. However, it will not be visible to you that the value inherited from MyArray is configured in the tag properties. – At least one array element must have specific limit extended property configured for indirectly referenced array logic to verify. For example, if MyArray[x].@Max is being used in logic, at least one array element of MyArray[] must have Max extended property configured if Max is not configured by MyArray. If this is not done, if you attempt to access Max in logic on MyArray in logic, the routine does not verify. – Under the following circumstances a data type default value is going to be used: - Array is accessed programmatically with indirect reference. - Array tag does not have the extended property configured. - Member of array does not have the extended property configured. For example for Array of SINT type, when max limit is called in logic for a member, the value 127 will be used. ·Removing Extended Properties You cannot remove extended properties that are accessed in logic when the project is online with the controller. The Max and Min check boxes in the Extended Properties box in the Tag Editor are unavailable. You have to go offline in order to remove the extended properties. Removing extended properties in logic on structure tags is unavailable at the tag level. For example, if MyUDTTag has 2 members, Mem1 being a DINT and the Mem2 being a SINT, if you define limit extended properties in Logic on both members, but are only accessing Max extended properties on Mem1, the Max check box is unavailable in the Extended Properties box in the Tag Properties Pane for both members. You are not able to remove the Max extended properties for MyUDTTag .Mem2 online. The same applies for Array tags. If limit extended properties is define on an array element and that element is accessed in logic, then limit extended properties cannot be removed from any of the array elements. 32 Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 Organizing Tags Chapter 2 Create a Tag The Tag Editor window lets you create and edit tags by using a spreadsheet-style view of the tags. IMPORTANT The Logix Designer application also automatically creates tags when you: – Add an element to a sequential function chart (SFC). – Add a function block instruction to a function block diagram. Follow these steps to create a tag by using the Logix Designer application. 1. On the Controller Organizer, right-click Controller Tags and choose Edit Tags. The Tag Editor window appears. 42350 2. Choose a scope for the tag. If You Use The Tag In more than one program within the project As a producer or consumer In any of the seven AXIS data types In a message In only one program within the project Program that will use the tag Name_of_controller Then Select 3. Type a name, data type, and description (optional) for the tag. 4. Specify the External Access and Constant attributes. See Chapter 4 on page 65 for information on the External Access and Constant attributes. Adding Extended Properties to a Tag To add extended properties to a tag: 1. Select the tag in the Tag Editor. 2. In the Tag Properties pane, check the properties that you want to add from the Extended Properties list. Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 33 Chapter 2 Organizing Tags The entries in the list depend on the tag’s data type. You can check more than one property. For data type Array and string Bool You can add the following extended property Engineering Unit State0 State1 Engineering Unit Min Max Engineering Unit DINT, INT, LINT, SINT, and REAL and corresponding array member The added properties are displayed in the Data properties category in the Tag Properties pane. Clear the check box to remove the property from the tag. This also removes the properties from the Data properties category. Note that once the property is removed, any value associated to the property is removed from the system. The list is not available for other types of tags. Min and Max for DINT, INT, LINT, SINT, and REAL Data Types Data Type DINT INT LINT SINT REAL Range -2,147,483,648...2,147,483,647 -32,768...32,767 0...32535129599999999 -128...127 -3.402823E38 to -1.1754944E-38 (negative values) and 0 and 1.1754944E-38 to 3.402823E38 (positive values) 34 Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 Organizing Tags Chapter 2 Create an Array Term Array Logix5000 controllers also let you use arrays to organize data. Definition A tag that contains a block of multiple pieces of data. ·An array is similar to a file. ·Within an array, each individual piece of data is called an element. ·Each element uses the same data type. ·An array tag occupies a contiguous block of memory in the controller, each element in sequence. ·You can use array and sequencer instructions to manipulate or index through the elements of an array. ·You organize the data into a block of one, two, or three dimensions. A subscript (s) identifies each individual element within the array. A subscript starts at 0 and extends to the number of elements minus 1 (zero based). To expand an array and display its elements, click the + sign. To collapse an array and hide its elements, click the – sign. This array contains six elements of the DINT data type. Six DINTs Elements of Timer_Presets 42367 The following example compares a structure to an array. This is a tag that uses the Timer structure (data type). Tag Name Data Type TIMER DINT DINT BOOL BOOL BOOL This is a tag that uses an array of the Timer data type. Tag Name Data Type TIMER[3] TIMER TIMER TIMER − Timer_1 + Timer_1.PRE + Timer_1.ACC Timer_1.EN Timer_1.TT Timer_1.DN − Timers + Timer[0] + Timer[1] + Timer[2] Rockwell Automation Publication 1756-PM004D-EN-P - September 2012 35 September 2012 . Because all the values are the same data type (DINTs) an array is used. click the + sign. Six DINTs Elements of Timer_Presets 42367 36 Rockwell Automation Publication 1756-PM004D-EN-P . a single timer instruction times the duration of several steps. To collapse an array and hide its elements.Chapter 2 Organizing Tags EXAMPLE Single-dimension array In this example. click the – sign. To expand an array and display its elements. This array contains six elements of the DINT data type. Each step requires a different preset value. 75 1 2 3 4 5 Description Position of first hole from leading edge of book Position of second hole from leading edge of book Position of third hole from leading edge of book Position of fourth hole from leading edge of book Position of fifth hole from leading edge of book In the Tags window.75 1. a two-dimension array is used.75 1.25 3. The first subscript indicates the hole that the value corresponds and the second subscript indications how many holes will be drilled (one…five). the dimension to the left increments by one.25 5. Subscript of Second Dimension 0 0 1 Subscript of First Dimension 2 3 4 5 1. This array contains a two-dimensional grid of elements.5 8.0 1.5 9. The machine requires a value for the position of each hole from the leading edge of the book. six elements x six elements.Organizing Tags Chapter 2 EXAMPLE Two-dimension array ATTENTION: A drill machine can drill one…five holes in a book. the elements are in the order depicted below.25 3. When the rightmost dimension starts over.5 9. 42367 The rightmost dimension increments to its maximum value then starts over.5 5. To organize the values into configurations. Rockwell Automation Publication 1756-PM004D-EN-P .5 7.September 2012 37 .5 2.5 7.5 9. On the Controller Organizer.September 2012 . Y is the number of elements in the second dimension. X is the number of elements in the first dimension. 38 Rockwell Automation Publication 1756-PM004D-EN-P . 42350 2. 3. The Tag Editor window appears. Z is the number of elements in the third dimension. right-click Controller Tags and choose Edit Tags. Type a name for the tag and select a scope for the tag.y] Data_type[x.z] Where Data_type is the type of data that the tag stores. If the tag is One-dimension array Two-dimension array Three-dimension array Then type Data_type[x] Data_type[x. Assign the array dimensions.Chapter 2 Organizing Tags Configuring an Array To create an array.y. 1. you create a tag and assign dimensions to the data type. Name (of data type): TANK Member Name Temp Deadband Step Step_time Preset Mix Data Type REAL REAL DINT TIMER DINT[6] BOOL ATTENTION: An array that is based on this data type would look like this example. ATTENTION: In a system of several tanks. DINT. Array of Recipes First Recipe This array contains three elements of the TANK data type. Members of the Recipe 42368 Rockwell Automation Publication 1756-PM004D-EN-P . BOOL. each tank can run a variety of recipes. a user-defined data type is used.Organizing Tags Chapter 2 Creating a User-defined Data Type EXAMPLE User-defined data types (structures) let you organize your data to match your machine or process.September 2012 39 . User-defined data type that stores a recipe. Because the recipe requires a mix of data types (REAL. so forth). Because several drill stations require the following mix of data. use these guidelines: · If you include members that represent I/O devices.September 2012 . Refer to “Address I/O Data” on page 19. Array of Drills First Drill This array contains four elements of the DRILL_STATION data type. Name (of data type): DRILL_STATION Member Name Part_advance Hole_sequence Type Hole_position Depth Total_depth Data Type BOOL CONTROL DINT REAL REAL REAL ATTENTION: An array that is based on this data type looks like this example. Multi-dimension arrays are not permitted in a user-defined data type.Chapter 2 Organizing Tags EXAMPLE User-defined data type that stores the data that is required to run a machine. you must use logic to copy the data between the members in the structure and the corresponding I/O tags. 40 Rockwell Automation Publication 1756-PM004D-EN-P . Data for the Drill 42583 Guidelines for User-defined Data Types When you create a user-defined data type. limit the array to a single dimension. use a user-defined data type. · If you include an array as a member. 2. right-click User-Defined. place members that use the same data type in sequence. More Efficient BOOL BOOL BOOL DINT DINT Less Efficient BOOL DINT BOOL DINT BOOL Creating a User-defined Data Type 1. SINT.Organizing Tags Chapter 2 · When you use the BOOL. On the Controller Organizer from the User-defined folder under Data Types. Choose New Data Type. or INT data types. Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 41 . Type a name and description for the user-defined data type.Chapter 2 Organizing Tags 3. 4. and description. select the style. data type. For each member of the user-defined data type. Click the External Access column. 7. 5. style. A description is optional. type a name. Click Apply. 42196 Limit any arrays to a single dimension. 42 Rockwell Automation Publication 1756-PM004D-EN-P . To display the value of the member in a different style (radix). Add as many members as needed.September 2012 . 6. and choose an attribute. You can check more than one property..1754944E-38 to 3. Engineering Units.402823E38 to -1. and State 1 properties to a data type or its member. and REAL IMPORTANT The list is unavailable for other types of data type members. and REAL Data Types Data Type DINT INT LINT SINT REAL Range -2. SINT.147... check the properties that you want to add from the Extended Properties list.768.648. SINT.September 2012 43 .1754944E-38 (negative values) and 0 and 1. Select the data type member in the Data Type Editor 2. 1.483.483. In the Data Type Editor Properties pane.647 -32...32535129599999999 -128. INT. The entries in the list depend on the selected member’s data type. their values are made available for use by some Rockwell Automation HMIs.32.2.Organizing Tags Chapter 2 Adding Extended Properties to a User-Defined Data Type You can add Min.. LINT.402823E38 (positive values) Rockwell Automation Publication 1756-PM004D-EN-P . Min and Max for DINT. Max. For data type Array and string Bool You can add the following extended property Engineering Unit State 0 State 1 Engineering Unit Min Max Engineering Units DINT..147.. These extended properties are added and modified in the Data Type Editor Properties pane.127 -3. LINT.767 0. INT. When these properties are added. State 0. It starts with the description of the tag and then adds the description of the member from the data type.Chapter 2 Organizing Tags Describing a User-defined Data Type Version 13. ·Descriptions in user-defined data types ripple through to the tags that use that data type. ·Description of an array tag ripples through to the elements and members of the array.Color Descriptions If Color Description Is Gray Black This Is Pass-through description Manually entered description 44 Rockwell Automation Publication 1756-PM004D-EN-P . Paste pass-through description – Use the data type and array description as a basis for more specific descriptions. Tank became West Tank. element.0 or later of the application. In this example. the Logix Designer application looks for an available description for a tag. The Logix Designer application uses different colors for descriptions.September 2012 . Table 6 . Append description to base tag – the Logix Designer application automatically builds a description for each member of a tag that uses a user-defined data type. This greatly reduces the amount of time you have to spend documenting your project. As you organize your user-defined data types. The Logix Designer application lets you automatically build descriptions out of the descriptions in your user-defined data types. or member. Pass through of descriptions – When possible. keep in mind the following features of the Logix Designer application. Under Application. Rockwell Automation Publication 1756-PM004D-EN-P . select Display. Check Show Pass-Through Descriptions and Append to Base Tag Descriptions. 1. The Work Station Options screen appears. Click OK. 4. In the Logix Designer application. from the Tools menu choose Options. 2. 3.Organizing Tags Chapter 2 Activate Pass-Through and Append Descriptions Follow these steps to use pass-through descriptions and append to base tag descriptions.September 2012 45 . Chapter 2 Organizing Tags Paste a Pass-Through Description Choose this command to paste a pass-through value of an item into the Description. Engineering Unit. Edit the description and press CTRL + Enter. On the Controller Tags screen. 2.September 2012 . and choose Paste Pass-Through. Follow these steps to use a pass-through description as the starting point for a more specific description. right-click the pass-through description. State 0. 46 Rockwell Automation Publication 1756-PM004D-EN-P . 1. or State 1 field of another item. constants. ABS(Tag_4).8]. Tag_1-Tag_2. Tag_3+4. ABS (Tag_4). For example. ·Keep the value of the tag or numeric expression within the range of bits of the integer tag. Tag_1-Tag_2. ·A numeric expression uses a combination of tags. then the value of the tag or numeric expression must be 0…9 (10 elements). and functions to calculate a value. For example. To indirectly (dynamically) reference an element. ·Use one subscript for each dimension of the array. and functions to calculate a value. operators. For example: [5]. INT. ·If the structure contains another structure as one of its members.Organizing Tags Chapter 2 Address Tag Data A tag name follows this format.2. use a tag or numeric expression that provides the bit number. operators. then the value of the index must be 0…31 (32-bits).[Index] = Optional Where Name Element Is Name that identifies this specific tag. use a tag or numeric expression that provides the element number. ·Keep the value of the tag or numeric expression within the dimensions of the array. constants. or DINT). [3. Name [Element] . Member Specific member of a structure. use additional levels of the. To indirectly (dynamically) reference a bit of an integer. Rockwell Automation Publication 1756-PM004D-EN-P . ·Use the element identifier only if the tag or member is an array. ·A numeric expression uses a combination of tags.7].September 2012 47 . if a dimension of an array contains 10 elements. Bit Index Specific bit of an integer data type (SINT.Member format to identify the required member.Bit or .Member [Element] . ·Use the member identifier only if the tag is a structure. Subscript or subscripts that point to a specific element within an array. For example. [2. Tag_3+4. For example. if the integer tag is a Dint (32-bits). Later.3 (a digital input point). The tags window displays alias information. create a tag with a name that describes the device. When the input turns on. 42360 The (C) indicates that the tag is at the controller scope. 1. · Assign a descriptive name to an I/O device. · Provide a more simple name for a complex tag. convert the descriptive tags to aliases for their respective I/O points or channels.Chapter 2 Organizing Tags Alias Tags An alias tag lets you create one tag that represents another tag. the other tag reflects the change as well. add the I/O modules to the I/O configuration of the controller. when wiring diagrams are available. 3.September 2012 .2 (a digital output point).Data. such as conveyor for the conveyor motor. When the alias tag turns on. drill_1_on is an alias for Local:0:O. drill_1_depth_limit is an alias for Local:2:I.1]. north_tank is an alias for tanks[0. You can even test your logic without connecting to the I/O. · When the value of one of the tags changes. the output tag also turns on. Program your logic by using the descriptive tag names. A common use of alias tags is to program logic before wiring diagrams are available. For each I/O device. 2. Finally. 4. · Use a descriptive name for an element of an array. the alias tag also turns on.Data. · Both tags share the same value. 48 Rockwell Automation Publication 1756-PM004D-EN-P . Use aliases in the following situations: · Program logic in advance of wiring diagrams. Data. Click the Ladder Display tab.Data. 2.Data. such as stop and conveyor_on.0> machine_on drill_1_on machine_on <Local:0:O. stop is an alias for Local:2:I.Organizing Tags Chapter 2 The following logic was initially programmed by using descriptive tag names.September 2012 49 .0> conveyor_on is an alias for Local:0:O. Click OK. Later.2> drill_1.Data.1> start <Local:2:I.part_advance conveyor_on <Local:0:O. 1. 3. 4. the tags were converted to aliases for the corresponding I/O devices.Data.Data.1 (the stop button on the operator panel) stop <Local:2:I. Check Show Tag Alias Information.0 The starter contactor for the conveyor motor) 42351 Display Alias Information Follow these steps to show (in your logic) the tag to which an alias points. choose Options. From the Tools menu. Rockwell Automation Publication 1756-PM004D-EN-P . Click another cell. To Select a tag Select a bit number >.Chapter 2 Organizing Tags Assign an Alias Follow these steps to assign a tag as an alias tag for another tag. To the right of the tag name. 42360 2. Choose the tag that the alias will represent.September 2012 . C. 50 Rockwell Automation Publication 1756-PM004D-EN-P . Click >. The Tag Editor window appears. Click the required bit. Click the tag name. A. Do This Double-click the tag name. 1. click >. 5. B. click the Alias For cell. right-click Controller Tags and choose Edit Tags. On the Controller Organizer. Select the scope of the tag. 3. 6. To the right of the tag name. The cell displays a 4. When index equals 1. Enter the desired setup in the tag. Use an ADD instruction to increment the tag value and point to the next element in the array. By changing the value of the tag. To Select a recipe from an array of recipes Load a specific machine setup from an array of possible setups Load parameters or states from an array. B.Organizing Tags Chapter 2 Assign an Indirect Address If you want an instruction to access different elements in an array. 4500 6000 3000 2500 The following table outlines some common uses for an indirect address. array[index] points here. Perform the required action on the first element. A. use a tag in the subscript of the array (an indirect address). you change the element of the array that your logic references. array[0] array[1] array[2] array[3] When index equals 2.September 2012 51 . array[index] points here. Rockwell Automation Publication 1756-PM004D-EN-P . one element at a time Log error codes Perform several actions on an array element and then index to the next element Use a tag in the subscript and Enter the number of the recipe in the tag. The north_tank.) EQU Equal Source A north_tank.step_time Preset 60000 Accum 0 EN DN When north_tank.000 ms).step 0 Dest north_tank.DN Add Source A ADD 1 Source B north_tank. · The controller computes the result of the expression and uses it as the array subscript.step 0 42358 Expressions You can also use an expression to specify the subscript of an array. such as + or -.step to the next number and that element of the timer_presets array loads into the timer.Chapter 2 Organizing Tags The following example loads a series of preset values into a timer.step_time.step_time is done. 52 Rockwell Automation Publication 1756-PM004D-EN-P . For example. north_tank.September 2012 .step] 60000 Dest north_tank.PRE 60000 north_tank.step exceeds the size of the array. The timer_presets array stores a series of preset values for the timer in the next rung.step 0 When north_tank. (The array contains elements 0…3. one value (array element) at a time. · An expression uses operators.step_time.step 0 Source B 4 MOV Move Source 0 Dest north_tank.step tag points to which element of the array to use. the instruction loads timer_presets[0] into the timer (60. to calculate a value. MOV Move Source timer_presets[north_tank.step equals 0. the rung increments north_tank. the rung resets the tag to start at the first element in the array.step_time. EXAMPLE Step through an array. when north_tank.DN / TON Timer On Delay Timer north_tank. Organizing Tags Chapter 2 You can use these operators to specify the subscript of an array. Table 7 .Format Expressions If the operator requires One value (tag or expression) Two values (tags.September 2012 53 . constants. or expressions) Use this format operator(value) value_a operator value_b Example ABS(tag_a) ·tag_b + 5 ·tag_c AND tag_d ·(tag_e ** 2) MOD (tag_f / tag_g) Rockwell Automation Publication 1756-PM004D-EN-P . Operator + * / ABS AND FRD Description Add Subtract/negate Multiply Divide Absolute value AND BCD to integer Operator MOD NOT OR SQR TOD TRN XOR Description Modulo Complement OR Square root Integer to BCD Truncate Exclusive OR Format your expressions as follows. September 2012 . EXAMPLE e For more information on handling major faults. The controller checks the array subscript in these instructions even if the rung is false. Transitional instructions also generate a major fault even if the rung is false. publication 1756-PM014. refer to the Logix5000 Controllers Major and Minor Faults Programming Manual. 54 Rockwell Automation Publication 1756-PM004D-EN-P .Chapter 2 Organizing Tags Array Subscript Out of Range Every instruction generates a major fault if the array subscript is out of range. or bit. user-defined data types. or Add-On Instructions • Trends • Controllers • Alarm messages (in configuration of ALARM_ANALOG and ALARM_DIGITAL tags) • Tasks • Property descriptions for a module in the Controller Organizer • Rung comments. In the description of your Produced tag. and Add-On Instructions • Engineering units and state identifiers added to tags.Organizing Tags Chapter 2 Tag Documentation The table outlines the four types of tags that can be created and the descriptions that you can document for each one. By creating an Alias tag. routines. A Produced tag refers to a tag that is consumed by another controller. Description When you create a tag without specifying a tag type. equipment phases. and optional custom localized language. Rockwell Automation Publication 1756-PM004D-EN-P . Since base tags enable you to create your own internal data storage. IMPORTANT The Logix Designer application automatically assigns what are called pass-through descriptions of the tags you have created. The application uses the default language if the current language's content is blank for a particular component of the project. However. default. user-defined data types. In the description of your Alias tag. structure tag member. Sequential Function Chart text boxes. You define all the localized languages that the project will support and set the current.September 2012 55 . You may or may not want to use these descriptions. you can describe the remote controllers that you want to make your Produced tag available through controller-to-controller messaging. you can describe how you want to use a produced tag’s data or the data-producing controller. you have the option to display project documentation variables for any supported localized language. such as: • Component descriptions in tags. you can use a custom language to tailor documentation to a specific type of project file user. A Consumed tag refers to a tag that is produced by another controller and whose data you want to use in your controller. you can document in your tag description the nature of the data being stored. you can assign your own name to an existing tag. the Logix Designer application automatically assigns your tag a default type of Base. you can describe the tag that your alias tag references. In the description of your Consumed tag. and Function Block Diagram text boxes You can store project documentation for multiple languages in a single project file rather than in language-specific project files. Tag Base Alias Produced Consumed Project Documentation With version 17 and later of the application. programs. see the online help. 56 Rockwell Automation Publication 1756-PM004D-EN-P . For more information on enabling a project to support multiple translations of project documentation. you can dynamically switch between languages as you use the application. either when programming in that language or by using the import/export utility to translate the documentation off-line and then import it back into the project.September 2012 .Chapter 2 Organizing Tags Enter the localized descriptions in your Logix Designer project. Once you enable documentation languages in the Logix Designer application. If forces are enabled and you install a force. · You cannot enable or disable forces for a specific module. or tag element. ATTENTION: Forcing can cause unexpected machine motion that could injure personnel. use forces to: · test and debug your logic. – – – – Enabling I/O forces causes input. You can only enable and disable forces at the controller level. IMPORTANT If you download a project that has forces enabled. Rockwell Automation Publication 1756-PM004D-EN-P . · You can enable I/O forces and SFC forces separately or at the same time.Chapter 3 Force I/O Introduction Use a force to override data that your logic either uses or produces. determine how the force will effect your machine or process and keep personnel away from the machine area. For example.September 2012 57 . Enable Forces For a force to take effect. tag collection. · temporarily keep your process functioning when an input device has failed. take these precautions. or consumed values to change. you enable forces. Use forces only as a temporary measure. produced. Before you use a force. Precautions When you use forces. They are not intended to be a permanent part of your application. the application prompts you to enable or disable forces after the download completes. Enabling SFC forces causes your machine or process to go to a different state or phase. the new force immediately takes effect. · check wiring to an output device. Removing forces may still leave forces in the enabled state. output. determine how the change will effect your machine or process and keep personnel away from the machine area. To determine status I/O forces Use any of the following ·Online toolbar ·FORCE status indicator ·GSV instruction Online toolbar SFC forces 58 Rockwell Automation Publication 1756-PM004D-EN-P . state to which the element is forced Disable or Remove a Force To stop the effect of a force and let your project execute as programmed. You can check force status. · Removing a force on an alias tag also removes the force on the base tag. Check Force Status Before you use a force.September 2012 ▼ .Chapter 3 Force I/O When forces are in effect (enabled). · You can disable or remove I/O and SFC forces at the same time or separately. a appears next to the forced element. Before you disable or remove forces. disable or remove the force. ATTENTION: Changes to forces can cause unexpected machine motion that could injure personnel. determine the status of forces for the controller. Rockwell Automation Publication 1756-PM004D-EN-P . It does not show that status of SFC forces. If the project contains any forces of this type. ·I/O forces are inactive (disabled). No forces of this type exist in the project.September 2012 59 . use it to determine the status of any I/O forces. FORCE Status Indicator Off Flashing Solid GSV Instruction IMPORTANT The ForceStatus attribute shows only the status of I/O forces. At least one force of this type exists in the project. they are overriding your logic. IMPORTANT The FORCE Status Indicator shows only the status of I/O forces. ·I/O forces are active (enabled). It does not show the status of SFC forces. ·At least one tag contains a force value. ·If you add a force of this type. ·I/O forces are inactive (disabled). Then ·No tags contain force values. This example shows how to use a GSV instruction to get the status of forces.Force I/O Chapter 3 The Online toolbar shows the status of forces. FORCE Status Indicator If your controller has a FORCE Status Indicator. they are not overriding your logic. ·Force values may or may not exist. the new force immediately takes effect Forces of this type are inactive. Forces tab This Enabled Disabled Installed None Installed Means ·If the project contains any forces of this type. It shows the status of I/O forces and SFC forces separately. Chapter 3 Force I/O where: Force_Status is a DINT tag. IMPORTANT Use these guidelines when forcing an I/O value. a produced tag). INT. such as an I/O tag. you cannot use forces. Forces remain even if the programming workstation is disconnected. · override your logic and specify the state of an output device. produced tag. – Removing a force from an alias tag removes the force from the associated base tag. or consumed tag. the longer it takes to execute the logic. DINT. force a BOOL. To determine if Forces are installed No forces are installed Forces are enabled Forces are disabled Examine this bit 0 0 1 1 For this value 1 0 1 0 When to Use I/O Force Use an I/O force to: · override an input value from another controller (that is. – An alias tag shares the same data value as its base tag. · If the data value is a SINT. I/O forces are held by the controller and not by the programming workstation. or DINT. The more values you force. 60 Rockwell Automation Publication 1756-PM004D-EN-P . a consumed tag). · override your logic and specify an output value for another controller (that is. you can force the entire value or you can force individual bits within the value. so forcing an alias tag also forces the associated base tag. INT. · override an input value from an input device. or REAL element or member. · If a produced tag is also Constant. · If the tag is an array or structure. SINT. IMPORTANT Forcing increases logic execution time.September 2012 . except for configuration data. · You can force all I/O data. Individual bits can have a force status of: – No force – Force on – Force off · You can also force an alias to an I/O structure member. determine how the force will effect your machine or process and keep personnel away from the machine area. produced. 2. Add an I/O Force To override an input value. 1. or consumed tag. 3. all existing I/O forces will also take effect. expand the tag to show the value that you want to force (that is. – If forces are enabled and you install a force. Before you use a force. Force an Input Value Forcing an input or consumed tag: · overrides the value regardless of the value of the physical device or produced tag. Right-click the tag and choose Monitor. Rockwell Automation Publication 1756-PM004D-EN-P . you cannot make it Constant. · does not affect the value received by other controllers monitoring that input or produced tag. When you enable I/O forces. produced tag. or consumed values to change. What is the state of the I/O Forces status indicator? If Off Flashing Solid Then note No I/O forces currently exist. – Enabling I/O forces causes input. it immediately takes effect. the new force immediately takes effect. Open the routine that contains the tag that you want to force. I/O forces are enabled (active). If necessary.September 2012 61 . When you install (add) a force. output value. Force an Output Value Forcing an output or produced tag overrides the logic for the physical device or other controller. Other controllers monitoring that output module in a listen-only capacity will also see the forced value. BOOL value of a DINT tag). output. use an I/O force. ATTENTION: Forcing can cause unexpected machine motion that could injure personnel. No I/O forces are active.Force I/O Chapter 3 · If a produced tag is forced. But at least one force already exists in your project. September 2012 .) If No Yes Then From the Logic menu. ATTENTION: Before you remove a force. 5. Go to step 4. Install the force value. Choose Yes to confirm. determine how the change will effect your machine or process and keep personnel away from the machine area. ATTENTION: Changes to forces can cause unexpected machine motion that could injure personnel. Press Enter. 62 Rockwell Automation Publication 1756-PM004D-EN-P . choose I/O Forcing > Enable All I/O Forces. determine how the change will effect your machine or process and keep personnel away from the machine area. Stop. Remove or Disable Forces This section describes how to remove and disable forces. forces remain in the enabled state and any new force immediately takes effect. type the value that you want to force the tag. To force a BOOL value Non-BOOL value Do this Right-click tag and choose Force On or Force Off. Go to step 3. Go to step 3. If you want to Stop an individual force Stop all I/O forces but leave all SFC forces active And Leave other forces enabled and in effect Leave the I/O forces in the project Remove the I/O forces from the project Then Remove an Individual Force Disable All I/O Forces Remove All I/O Forces Remove an Individual Force ATTENTION: If you remove an individual force. In the Force Mask column for the tag. Open the routine that contains the force that you want to remove. Before you disable or remove forces. What is the language of the routine? If SFC Ladder logic Function block Structured text Then Go to step 4. 2. 1.Chapter 3 Force I/O 4. Are I/O forces enabled? (See step 1. Disable All I/O Forces To disable. Click Yes to confirm. Right-click a tag or element that has the force and choose Remove Force. BOOL value of a DINT tag.Force I/O Chapter 3 3.September 2012 63 . choose Logic>I/O Forcing>Disable All I/O Forces. for example. 4. choose Logic>I/O Forcing>Remove All I/O Forces. Click Yes to confirm. If necessary. expand the tag to show the value that is forced. Right-click a tag that has the force and choose Monitor. Remove All I/O Forces To remove. Rockwell Automation Publication 1756-PM004D-EN-P . Chapter 3 Force I/O Notes: 64 Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 . you can control how external applications and devices can access tags. Using this attribute also can help improve system performance by reducing the number of tags RSLinx has to maintain. It has possible values of Read/Write. and None. version 18 or later of the application. you can also reduce the time required to develop HMI screens. Read Only. there are two tag attributes that allow you to control access to tag data.Chapter 4 Data Access Control Introduction In the Logix platform. By using these two attributes. • PLC/SLC controllers. This volume can impact the performance of the RSLinx data server and other related applications. by using FactoryTalk Security software. See page 77 for more information on the Constant attribute. scan. • other Logix controllers. and cache. • PanelView terminals. These attributes are: • External Access • Constant The External Access attribute controls how external applications. External Access By using the External Access attribute. such as HMIs. Also.September 2012 65 . it is possible to control which users are permitted to change tags designated as constants in the Logix Designer application. This process can help you manage the thousands of tags you might have in a project that have similar names that can get easily confused when referencing them in applications or devices. Also. • other third-party software. External applications and devices include: • RSLinx Classic and RSLinx Enterprise software. The Constant attribute value determines if a tag can be modified by controller logic. you can help safeguard tag data by preventing unwanted changes to tag values. • FactoryTalk Historian software. See “Configure External Access” on page 66. Rockwell Automation Publication 1756-PM004D-EN-P . can access tags. by reducing the number of tags exposed to external applications. External applications cannot read or change the tag’s value. the default external access tag retains the value of the user’s previous choice. External applications can read. For example. and type of the tag. and Add-On Instruction scoped tags. only the safety tags will be disabled from being accessed.(1) Out-of-box is Read Only.Chapter 4 Data Access Control Configure External Access You configure external access from a menu when you create a new tag or data type. If the controller is in safety locked mode.September 2012 . New Tag Dialog. they can be made in the User-defined Data Type Editor. Read Only. See Important note below. External Access Settings Read/Write Read Only None Description External applications and devices have full access to the tag and can read and change the tag’s value.(1) Equipment phase output parameters (1) The External Access default value for tag creation is stored per Windows login account. The following table describes the values. If the tag is Alias Controller/program scoped and equipment phase input parameters Default value is Same as its target. but cannot change. Thereafter. controller. You can also modify that value just like other tag attributes. and the Tag Properties Dialog. regardless of their External Access settings. the default external access tag retains the value of the user’s previous choice. The standard tags will have the same behavior as in the unlocked mode. External access applies to all program. These changes can be made throughout the application. None from the External Access box on the following Logix Designer dialog boxes: • New Tag (See page 67) • Tag Properties (See page 69) The default value in the External Access box is dependent on the usage. when creating a new tag. the tag’s value. Out-of-box is Read/Write. when creating a new tag. External Access Options You can choose one of three options—Read/Write. Thereafter. 66 Rockwell Automation Publication 1756-PM004D-EN-P . IMPORTANT The Logix Designer application has full access to all tags. the External Access box will update its value to be the same as the external access of the base target. Follow these steps. The External Access box on the New Tag dialog box lets you assign the external access attribute for the tag being created. Rockwell Automation Publication 1756-PM004D-EN-P . Configure External Access in the New Tag Dialog Box You can create these types of tags on the New Tag dialog box: • Base tag • Alias tag • Produced tag • Consumed tag The parameters on the dialog box depend on the type of tag you are creating. the External Access box is disabled. For tag descriptions.September 2012 67 . However. 1. see page 24. On the Controller Organizer. See “External Access Availability” on page 72 for additional tag considerations.Data Access Control Chapter 4 IMPORTANT For Alias type. You are not allowed to change the external access of an alias tag. See “‘Go To’ Search Menu” on page 71 for procedures to locate the base tag for an alias. right-click Controller Tags and choose New Tag . 3. 2. There may be many alias tags in a program. the External Access box is dimmed for an alias tag. From the External Access menu. Click OK .Chapter 4 Data Access Control The New Tag Dialog Box appears. See page 71 for details. choose an external access option. As shown in the example below. To locate an associated base tag to assign an external access. choose a tag type. 4. 68 Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 . use the ‘Go To’ feature. From the Type menu. The Connection button (next to the Type box) becomes active when either a produced or consumed tag type is selected. Set Up External Access in the Tag Properties Dialog Box The Tag Properties dialog box is used to edit properties of existing tags. Rockwell Automation Publication 1756-PM004D-EN-P . Follow these steps to choose an external access option for an existing tag. such as base and alias. The button accesses a dialog box for setting up produced/consumed tag connections. You can change tag attributes and modify tag types. choose an external access option. right-click a tag and choose Edit (tag name) Properties. choose a tag type. On the Tag Editor window. see “External Access Availability” on page 72. publication 1756-PM011. 1. See the Logix5000 Controllers Produced and Consumed Tags Programming Manual.Data Access Control Chapter 4 For other tag considerations. From the External Access menu. From the Type menu. 3. 2.September 2012 69 . The Tag Properties dialog box appears. If a tag is a module tag. View and Select External Access Status on the Tag Editor Window You can view the external access status of a tag in the Tag Editor window.September 2012 . To select multiple individual rows. ‘Read Only’. Click Set External Access for (tag name) to select an external access option. Click OK . 4. Follow these steps to select multiple rows and set the external access at one time on the Tag Editor. See “External Access Availability” on page 72 for other considerations. A menu displays. The External Access column displays the tag as ‘Read/Write’. or ‘None’.Chapter 4 Data Access Control The External Access box is dimmed for an alias tag. All highlighted rows that are enabled for changing External Access will change their external access setting. 1. Right-click a selected tag. the only external access option is Read/Write. hold down the Ctrl key and click the desired rows. 2. 3. 70 Rockwell Automation Publication 1756-PM004D-EN-P . choose a target of the alias tag. Follow these steps to locate a base tag. With the Tag Editor window open. choose Base Tag. ‘Go To’ Search Menu The external access setting of an alias tag can only be changed through its base tag. select the desired alias tag and choose Go To. The Go To window appears. The target is located with a black box around it. 3.September 2012 71 . The ‘Go To’ option on the Search menu of the Logix Designer application is a convenient way to find the base tag among all the cross-reference records.Data Access Control Chapter 4 See “External Access Availability” on page 72 for considerations when the External Access column is disabled. all alias tags in this chain will display in a list in the Go To column. From the Go To menu. Click Go To. The box will display the target of the alias tag. In the Go to what column. If there is an alias chain. from the Logix Designer Search menu. 4. 2. Rockwell Automation Publication 1756-PM004D-EN-P . 1. • the controller is safety-locked and the tag is a safety tag. • the controller is user-locked online. • the Scope is an equipment phase and the equipment phase feature is not activated in the current license. IMPORTANT The External Access box is always disabled for any tag whose data type is Alarm Analog or Alarm Digital. all elements: • must have the same external access level. If you change the Type box from Base to Alias. • of all data members for predefined or module-defined data types will have the same external access setting. Dialog Box/Window New Tag Tag Properties Tag Editor 72 Rockwell Automation Publication 1756-PM004D-EN-P . • the controller is user-locked online from another computer. • the redundancy controller is in any state that does not allow changes. Considerations The External Access box is disabled if: • the tag is an alias tag. bit. The External Access box is disabled if: • you do not have permission to change the external access settings. • an external access change on the tag results in an update on all tag members.Chapter 4 Data Access Control External Access Availability The following table describes the conditions in which the External Access box is disabled. Only the safety tags’ External Access cell is disabled. For tags of Predefined (Atomic and Structural). the External Access box becomes disabled and appears blank. For Array tags. • the row represents an expanded array dimension. • the controller is in hard-run mode. • the Scope is an equipment phase and the equipment phase feature is not activated in the current license. If you choose a target for an alias tag in the Alias For box. The external access setting of an alias tag can only be changed through its base tag.September 2012 . all of these tag members will have the same external access level because: • they are all hard-coded to ‘Read/Write’ and you can only view. The external access status is always Read/Write for these data types. or data member. • of each data member for user-defined type (UDT) and Add-On Instruction will have the more restrictive external access setting between the element external access setting and the external access setting of the member in the type definition. • the controller is in hard-run mode. The External Access box is disabled if: • you do not have permission to change the external access settings. this value. Module-defined Data Types and String. • the controller is safety-locked and the tag is a safety tag. • the controller is user locked online. • the redundancy controller is in any state that does not allow changes. the External Access box remains disabled and the external access value appears in the External Access box. • the tag is an alias tag. not change. You also cannot change external access for the data type members. • the tag is an alias tag. September 2012 73 . The Set External Access entry is added to the bottom of the row header context menu. Topic Modify existing data type Considerations The External Access column is disabled if: • you do not have permission to change the external access settings. • If the member’s data type is User-defined and the child-member has a different external access level from its parent. The following table describes the conditions in which the External Access column is disabled. For example. Module-defined. External Access cells for the child-members are disabled on the User-defined Data Type dialog box. the member that represents that parameter in the Add-On Instruction data type cannot be written. the more restrictive external access level is applied. • You can only set external access for the top members of that User-defined data type. Strings type (1) If you have User-defined Data Type Modify permission. The external access level of the parent member is given to its child-members. Note: Data type size is not affected by the external access attribute. • the data type is applied to tags and the controller is online.Data Access Control Chapter 4 User-defined Type Considerations The three external access options—Read/Write (default). • If the member’s data type is Predefined structural. if an input parameter is defined with external access of read only.(1) • the redundancy controller is in any state that does not allow changes. Add-On Instructions External Access Considerations External Access settings can be used with parameters and local tags of Add-On Instructions. Three external access rules apply for members of User-defined data types. you cannot set external access of child-members. The external access column is always visible but disabled. module-defined. but it is always disabled. Rockwell Automation Publication 1756-PM004D-EN-P . or String. None—are chosen from the External Access column on the Data Type dialog box. Read Only. you also can modify external access of a User-defined data type. Predefined. September 2012 . • InOut parameter .the External Access box is disabled and blank. Add-0n Instruction Parameters and Tags Local tag Input parameter Output parameter EnableIn parameter EnableOut parameter InOut parameter Read Only Not Applicable Read/Write Read Only None External Access Options The external access for an Add-On Instruction tag can be chosen from the box on the New Tag dialog box or from the External Access column on the Tag Editor window.the External Access box is enabled and the displayed value is your last selection when creating an equipment phase output parameter or Add-On Instruction output parameter.the External Access box is disabled and the displayed value is None. • Local tag .the External Access box is enabled and the displayed value is your last selection when creating an equipment phase input parameter or Add-On Instruction input parameter. The external access of an Add-On Instruction’s parameters and local tags can be configured in the Add-On Instruction Definition dialog box and on the Add-On Instruction Parameters and Local Tags dialog boxes. 74 Rockwell Automation Publication 1756-PM004D-EN-P . the external access type is equal to the type configured for the base local tag.Chapter 4 Data Access Control The table below describes the External Access options for various Add-On Instruction parameters and tags. For alias parameters. • Output parameter . Dialog Box/Window New Add-On Instruction Parameter or Local Tag Considerations If the current usage is: • Input parameter . • no change if you switch between Input. or Read Only.Parameters Tab Add-On Instruction Definition . which are blank. • Local tag . • EnableIn and EnableOut parameters. • Output parameter . • the row represents an expanded array dimension. • no change if you switch between Input and Output parameters.September 2012 75 .(1) • the controller is online. • the Add-On Instruction is in Source Protection mode.Local Tags Tab Add-On Instruction Edit Tags (1) If you have Add-On Instruction Modify permission. The External Access column is disabled if: • EnableIn and EnableOut parameters. • InOut parameter .External Access column cell is blank and disabled. • the Add-On Instruction is in Source Protection mode. changing usage causes the External Access column auto update to default to: • Input parameter . When creating a new parameter. bit. Changing external access attributes will cause: • an error message if you change a tag from Input or Output parameter to InOut parameter and the present attribute is either Read/Write. you also can modify external access of an Add-On Instruction tag. If you change the usage from InOut parameter to: • Input or output parameter . • InOut parameter . Changing external access attributes will cause: • a warning message if you change a tag from Input or Output parameter to InOut parameter and the present attribute is either Read/Write. The External Access box also is disabled if: • you do not have permission to change external access settings. • Local tag . or data member.equipment phase input parameter and Add-On Instruction input parameter. Rockwell Automation Publication 1756-PM004D-EN-P .equipment phase output parameter and Add-On Instruction output parameter.Data Access Control Chapter 4 Dialog Box/Window Parameters/Local Tab Properties Considerations No change is applied to the External Access box if you switch the usage among Input parameter. • the value of the external access updates to the new target for an alias.(1) • the controller is online.equipment phase input parameter and Add-On Instruction input parameter. bit.(1) • the controller is online. • the Add-On Instruction is in Source Protection mode. or data member. or data member. • the Add-On Instruction is in Source Protection mode. except when the usage is a Local tag.the External Access is updated to None and the box is disabled.the External Access box is enabled and your last selection for creating an equipment phase/Add-On Instruction input parameter or an equipment phase/Add-On Instruction output parameter is displayed accordingly. When creating a new parameter. the box is disabled. • the row represents an expanded array dimension. Output parameters and Local tag • the value of the external access updates to the new target for an alias. • you do not have permission to change the external access settings. Note: External access is not applicable for InOut parameters because they are just references until invoked. or Read Only. The External Access column is disabled if: • InOut parameters. • the tag is an alias tag. which default ‘Read Only’. • Output parameter . Output parameter or Local tag. • the tag is an alias tag. • you do not have permission to change the external access settings. The External Access column is disabled if: • you do not have permission to change external access settings. changing usage causes the External Access column auto update to default to: • Input parameter .External Access column cell is blank and disabled. • the tag is an alias tag.(1) • the controller is online.equipment phase output parameter and Add-On Instruction output parameter. which default Read Only. Add-On Instruction Definition . • the row represents an expanded bit.external access is updated to None. EnableIn and EnableOut parameters Add-on Instruction InOut parameters Equipment phase output parameters Members of all data types Default External Access Read/Write Read Only Read/Write Read/Write Read Only N/A Read Only Read/Write 76 Rockwell Automation Publication 1756-PM004D-EN-P . Only eligible tags that are set to either Read/Write or Read Only will display in the menu.Chapter 4 Data Access Control Tag Mapping Considerations Only tags with external access settings of Read/Write or Read Only can be mapped to a PLC-2 controller and PLC-5/SLC controllers. Imported Tag Behavior The Logix Designer application preforms a check to verify an imported program file has a valid external access value. A default value is assigned to unspecified tags that are imported from programs that have software with versions earlier than 18. and None. Dialog Box/Window PLC-2. an error message displays.September 2012 . Read Only. If you manually type the name of a tag whose external access is set to None. An error message displays in the Logix Designer application for imported files that contain tags with any value other than Read/Write. • Click OK. • Choose a tag from the Name box. PLC-5/SLC Mapping Considerations To map a tag: • Type a file number. Object Name Controller and program-scoped standard tags All safety tags Add-on Instruction local tags Add-on Instruction Input parameters Add-on Instruction Output. You cannot pass a constant tag to an InOut parameter that is not also designated as a constant value. see the FactoryTalk Security System Configuration Guide. For all other conditions.September 2012 77 . it cannot be written to within the Add-On Instruction. To change the value of a constant. Add-On Instruction input and output parameters. publication FTSEC-QS001. TIP You cannot pass a constant value tag as an argument to an Output parameter of an Add-On Instruction. and local tags. FactoryTalk security is used to control who is permitted to modify values of constants and who can modify the constant attribute of a tag. the default value is unchecked. When you designate an InOut parameter as a constant. the default constant setting of this tag is the same as its target tag. For details on setting permissions. For an alias tag.Data Access Control Chapter 4 Constant Value Tags Version 18 and later of the application. Tags that cannot be designated as constants are User-defined type members. you must have the Tag: Modify Constant Property permission. indicating the tag is not a constant value tag. A check mark in the Constant box on tag creation dialog boxes and tag editor/monitor windows indicates a ‘constant’ designation. you must have the Tag: Modify Constant Tag Values permission. To modify the constant attribute of a tag. you can designate tags as constants to protect them from being changed programatically via: • the controller programming application. • logic in the controller. Rockwell Automation Publication 1756-PM004D-EN-P . 3. 1. Check Constant. right-click Controller Tags and choose New Tag. From the Type menu. 4. Click OK .Chapter 4 Data Access Control Configure Constant Tags This section describes the various ways a constant attribute can be configured. 2. Set Up a Constant in the New Tag Dialog Box Follow these steps to configure a tag as a constant on the New Tag dialog box.September 2012 . choose a tag type. 78 Rockwell Automation Publication 1756-PM004D-EN-P . On the Controller Organizer. Configure a Constant in the Tag Properties Dialog Box Follow these steps to designate a tag as a constant on the Tag Properties dialog box. The New Tag Dialog Box appears. See “Constant Checkbox Availability” on page 81 for considerations. choose a tag type. From the Type menu. Check Constant. 2.Data Access Control Chapter 4 1. See “Constant Checkbox Availability” on page 81 for considerations. right-click a tag and choose Edit (tag name) Properties.September 2012 79 . The Tag Properties dialog box appears. On the Tag Editor window. 4. 3. Rockwell Automation Publication 1756-PM004D-EN-P . Click OK. September 2012 . An error message displays if a user tries to change the data type of a constant tag to a data type that cannot be constant. all members of the tag take on the same setting. IMPORTANT In the Tag Monitor window. the constant setting of the tag displays in the same Constant column as shown in the above illustration. A menu appears. Follow these steps to add a constant value in the Tag Editor window. 1. The Constant column also is available on the Equipment Phase Tag Edit window and Equipment Phase Tag Monitor window. you cannot change the value. 2. right-click Controller Tags and choose Edit Tags.Chapter 4 Data Access Control Designate a Constant in the Tag Editor The Constant column on the Tag Editor window lets you designate tags that cannot be modified in the Logix Designer program. 80 Rockwell Automation Publication 1756-PM004D-EN-P . The Constant property applies to an entire tag. The Tag Editor window appears. On the Controller Organizer. Click the checkbox in the Constant column. However. The Constant column cells are blank for members of the constant tag. only the safety tags will be disabled from being accessed. publication 1756-PM015. see the Logix5000 Controllers Information and Status Programming Manual.) • the new tag is a Consumed tag.Data Access Control Chapter 4 Constant Checkbox Availability The state of the Constant checkbox depends on a number of conditions. • the tag’s Data Type is not a data table-backed type. Rockwell Automation Publication 1756-PM004D-EN-P . The value of a constant tag can be modified by using the Tag Monitor window if you have both standard Tag: Modify Values permission and Tag: Modify Constant Tag Values permission. • you do not have permission to modify tag properties (Factory Talk Security Tag Modify is denied.September 2012 81 . • the tag’s Usage setting is not ‘InOut’. Dialog Box/Window New Tag Considerations The Constant box is disabled if: • the tag is an alias tag. You cannot modify a constant value in any of the language editors or any other tag browser. For controller logging. • the Add-On Instruction is in Source Protection mode. Tag Properties Tag Editor Tag Monitor (1) If the controller is in safety-locked mode. the standard tags will have the same behavior as in the unlocked mode. Any modifications to the values of constant tags are recorded in the Controller Log for future reference. • redundancy controller is in any state that does not allow changes.(1) • if the Scope is an equipment phase and the equipment phase feature is not activated in the current license. The Constant value box will be disabled in the Tag Properties dialog box only if the tag is a safety tag. • the controller is safety-secured and the tag is a safety tag. Same considerations apply as for New Tag above. • the Factory Talk Security action is not enabled for changing constant value property of a tag. The icon in the Value column indicates that you are changing a constant value tag’s value. • the controller is in hard-run mode. Appropriate usage of Constant tags is monitored by logic verification.September 2012 . Output. By denoting an InOut parameter of an Add-On Instruction as a constant.Chapter 4 Data Access Control Add-On Instructions Constant Value Considerations The Constant attribute applies only to InOut parameters. The project will fail verification if this type of write is attempted. The Constant attribute will not apply to Input. that parameter cannot be written to. it means that within the Add-On Instruction. It will not apply to Add-On Instruction Local tags. EnableIn and EnableOut Add-On Instruction parameters. The default setting of the property will be not a Constant Value. 82 Rockwell Automation Publication 1756-PM004D-EN-P . September 2012 83 .Index A access external 65 add extended properties to a tag 33 add extended properties to user-defined data type 43 Add-On Instruction constant value considerations 82 external access variables 74 address assign indirect 51 tag 47 tag I/O module 19 alias create 50 show/hide 49 use of 48 array calculate subscript 52 create 38 index through 51 organize 29 overview 35 availability constant value 81 external access 72. 73 user-defined data type external access 73 constant value availability 81 dialog box 78 tag editor 80 E electronic keying I/O 12 enable force 57 exact match electronic keying 13 keying 12 expression calculate array subscript 52 extended properties 25 adding extended properties to a tag 33 user-defined data type 43 external access 65 Add-On Instruction 73 availability 72. 62 document tag description 44 user-defined data type 44 B buffer I/O data 20 C communication format 8 ownership 9 I/O module 8 module I/O configuration 7 compatible keying 12 configure external access 66 I/O module 7 connection direct 8 listen-only 9 overview 8 rack-optimized 8 reduce the number of 8 considerations Add-On Instructions constant value 82 external access 73 external access 72. 61 I/O 19 table ?See tag (organize) type choose 25 overview 25 structure 25 description tag 44 user-defined data type 44 direct connection 8 disable electronic keying 17 force 58. 73 configure 66 configure tag dialog 67 configure tag properties 69 options 66 user-defined data type considerations 73 view tag editor 70 Rockwell Automation Publication 1756-PM004D-EN-P . 73 tag properties 78 value configuration 78 value tags 77 controller tags 27 use of 27 create alias 50 tag 33 user-defined data type 41 D data block See array (create) force 60. 62 requested packet interval (RPI) 8 S scope guidelines 29 tag 27 sequential function chart force element 57 structure create 41 organize 29 overview 25 user-defined 39 structured text force a value 57 Studio 5000 Engineering and Design Environment 5 symbol See alias. SINT. 62 safety precautions 57 tag 60.Index F file ?See array force disable 58.September 2012 . 61 function block diagram force a value 57 N name guidelines for tag 29 reuse of tag name 27 O ownership I/O module 9 P pass-through description 44 program tags 27 project documentation 55 G global data ?See scope I I/O module buffer data 20 communication format 8 configuration 7 configure 7 document ?See alias electronic keying 12 ownership 9 synchronize with logic 20 tag address 19 update period 8 index See indirect address indirect address 51 format 47 use of expression 52 R rack-optimized connection 8 remove force 58. 62 enable 57 options 60 remove 58. K keying ?See electronic keying L ladder logic force a value 57 override a value 57 local data See scope Logix Designer application 5 tag T address 47 alias 48 array 35 assign dimensions 38 constant value 77 configuration 78 create 33 create alias 50 data type 25 dialog external access 67 editor view external access 70 M memory allocation for tags 25 Min and Max for DINT. and REAL data types 34. 43 module I/O configuration 7 84 Rockwell Automation Publication 1756-PM004D-EN-P . LINT. INT. September 2012 85 . 73 user-defined data type external access 73 Rockwell Automation Publication 1756-PM004D-EN-P .Index force 60. 61 guidelines 29 I/O 19 mapping considerations 76 memory allocation 25 name 27 organize 29 overview 23 properties external access 69 reuse of name 27 scope 27 type 24 U user-defined data type create 41 external access variables 73 guidelines 40 overview 39 V variables constant value 81 external access 72. Index 86 Rockwell Automation Publication 1756-PM004D-EN-P .September 2012 . . Installation Assistance If you experience a problem within the first 24 hours of installation. At http://www. You must provide a Customer Support case number (call the phone number above to obtain one) to your distributor to complete the return process. sample code and links to software service packs. you can find technical manuals.Ş.rockwellautomation.com/support/americas/phone_en.com/literature/. we offer TechConnect support programs. For an additional level of technical phone support for installation. contact your local distributor or Rockwell Automation representative. Tel: +90 (216) 5698400 Publication 1756-PM004D-EN-P . technical and application notes.com/support/. available at http://www.rockwellautomation. follow these procedures. You can contact Customer Support for initial help in getting your product up and running.com/support/. or contact your local Rockwell Automation representative. 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