Rockwell Automation Allen-Bradley Logix 5000 Series User manual

Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
Supercedes Publication 1756-PM009I-EN-P - September 2020
Programming Manual
Original Instructions
Logix 5000 Controllers
Function Block Diagram
1756 ControlLogix, 1756 GuardLogix, 1769 CompactLogix,
1769 Compact GuardLogix, 1789 SoftLogix, 5069
CompactLogix, 5069 Compact GuardLogix, Studio 5000
Logix Emulate

Logix 5000 Controllers Function Block Diagram
2 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
Important User Information
Read this document and the documents listed in the additional resources section about installation, configuration, and
operation of this equipment before you install, configure, operate, or maintain this product. Users are required to familiarize
themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws,and standards.
Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to
be carried out by suitably trained personnel in accordance with applicable code of practice.
If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be
impaired.
In no event will Rockwell Automation, Inc. be responsible orliable 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, whichmay 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.
IMPORTANT
Identifies information that is critical for successful application and understanding of the product.
Labels may also be on or inside the equipment to provide specific precautions.
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.
ARC FLASH HAZARD: Labels may be on or inside the equipment, for example, a motor control center, to alert people to potential Arc Flash. Arc Flash will cause
severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL Regulatory requirements for safe work practices and for Personal
Protective Equipment (PPE).
Rockwell Automation recognizes that some of the terms that are currently used in our industry and in this publication are not in
alignment with the movement toward inclusive language in technology. We are proactively collaborating with industry peers to
find alternatives to such termsand making changes to our products and content. Please excuse the use of such terms in our
content while we implement these changes.

Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 3
Summary of changes
This manual includes new and updated information. Use these reference
tables to locate changed information.
Grammatical and editorial style changes are not included in this summary.
Global changes
None in this release.
New or enhanced features
This table contains a list of topics changed in this version, the reason for the
change, and a link to the topic that contains the changed information.
Change
Topic
Updated Legal notices.
Legal notices on page 8

Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 5
Table of Contents
Studio 5000 environment ...........................................................................7
Additional resources....................................................................................8
Legal notices.................................................................................................8
Chapter 1
Introduction................................................................................................11
Choose the function block elements ........................................................ 12
Choose a tag name for an element ........................................................... 12
Define the order of execution....................................................................13
Data latching ........................................................................................13
Order of execution ...............................................................................15
Resolve a loop .......................................................................................16
Resolve data flow between two blocks................................................17
Create a one scan delay........................................................................17
Summary...............................................................................................18
Identify any connectors.............................................................................18
Define program/operator control.............................................................18
Add a sheet..................................................................................................21
Add a function block element....................................................................21
Use functions....................................................................................... 22
Create a text box.........................................................................................23
Language switching ............................................................................ 24
Connect elements...................................................................................... 25
Show or hide a pin............................................................................... 25
Wire elements together ...................................................................... 25
Mark a wire with the Assume Data Available indicator ................... 25
Assign a tag ................................................................................................ 26
Create and assign a new tag............................................................... 26
Assign an existing tag......................................................................... 27
Assign an immediate value (constant)..................................................... 28
Use an IREF ......................................................................................... 28
Enter a value in the tag of a block ...................................................... 28
Connect blocks with an OCON and ICON .............................................. 28
Add an OCON...................................................................................... 29
Add an ICON ....................................................................................... 29
Rename a wire connector................................................................... 29
Rename a connector group ................................................................ 29
Verify the routine ...................................................................................... 30
Summary of changes
Preface
Program a Function Block
Diagram
Index

Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 7
Preface
This manual shows how to program Logix 5000 controllers with the function
block diagram (FBD) programming language. This manual is one of a set of
related manuals that show common procedures for programming and
operating Logix 5000 controllers.
For a complete list of common procedures manuals, refer to the Logix 5000
Controllers Common Procedures Programming Manual, publication
1756-PM001.
The term Logix 5000 controller refers to any controller based on the Logix
5000 operating system.
Rockwell Automation recognizes that some of the terms that are currently
used in our industry and in this publication are not in alignment with the
movement toward inclusive language in technology. We are proactively
collaborating with industry peers to find alternatives to such terms and
making changes to our products and content. Please excuse the use of such
terms in our content while we implement these changes.
The Studio 5000 Automation Engineering & Design Environment® combines
engineering and design elements into a common environment. The first
element is the Studio 5000 Logix Designer® application. The Logix Designer
application is the rebranding of RSLogix 5000® software and will continue to
be the product to program Logix 5000™ controllers for discrete, process,
batch, motion, safety, and drive-based solutions.
The Studio 5000® environment is the foundation for the future of
Rockwell Automation® engineering design tools and capabilities. The Studio
5000 environment isthe one place for design engineers to develop all
elements of their control system.
Studio 5000 environment

Preface
8 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
These documents contain additional information concerning related
Rockwell Automation products.
Resource
Description
Industrial Automation Wiring and Grounding Guidelines,
publication 1770-4.1
Provides general guidelines for installing a Rockwell
Automation industrial system.
Product Certifications webpage, available at
http://ab.rockwellautomation.com
Provides declarations of conformity, certificates, and
other certification details.
View or download publications at
http://www.rockwellautomation.com/literature. To order paper copies of
technical documentation, contact the local Rockwell Automation distributor
or sales representative.
Rockwell Automation publishes legal notices, such as privacy policies, license
agreements, trademark disclosures, and other terms and conditions on the
Legal Notices page of the Rockwell Automation website.
End User License Agreement (EULA)
You can view the Rockwell Automation End User License Agreement (EULA)
by opening the license.rtf file located in your product's install folder on your
hard drive.
The default location of this file is:
C:\Program Files (x86)\Common Files\Rockwell\license.rtf.
Open Source Software Licenses
The software included in this product contains copyrighted software that is
licensed under one or more open source licenses.
You can view a full list of all open source software used in this product and
their corresponding licenses by opening the oss_license.txt file located in your
product's OPENSOURCE folder on your hard drive. This file is divided into
these sections:
•Components
Includes the name of the open source component, its version number,
and the type of license.
•Copyright Text
Includes the name of the open source component, its version number,
and the copyright declaration.
•Licenses
Includes the name of the license, the list of open source components
citing the license, and the terms of the license.
The default location of this file is:
Additional resources
Legal notices

Preface
Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 9
C:\Program Files (x86)\Common Files\Rockwell\Help\<product
name>\Release Notes\OPENSOURCE\oss_licenses.txt.
You may obtain Corresponding Source code for open source packages
included in this product from their respective project web site(s).
Alternatively, you may obtain complete Corresponding Source code by
contacting Rockwell Automation via the Contact form on the Rockwell
Automation website:
http://www.rockwellautomation.com/global/about-us/contact/contact.page.
Please include "Open Source" as part of the request text.

Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 11
Chapter 1
Program a Function Block Diagram
To make it easier to navigate through a function block routine, divide the
routine into a series of sheets.
•Sheets help organize function blocks and make them easier to locate.
They do not affect the order in which the function blocks execute.
•When the routine executes, all the sheets execute.
•In general, use one sheet for each device, such as a motor or valve.
Example
Function block routine divided into sheets:
Introduction

Chapter 1 Program a Function Block Diagram
12 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
Use these elements to control a device:
Guidelines to choose the function block elements:
To:
Use this element:
Supply a value from an input device or tag
Input reference (IREF)
Send a value to an output device or tag
Output reference (OREF)
Perform an operation on an inputvalue or values and produce an outputvalue
or values
Function block or function
Functions are similar to function blocks, but do not require backing tags, require
less memory than function blocks, sometimes execute more quickly, and use
less space in a function block diagram.
Tip:
Functions are available only in Logix Designer versions 32 and later on
CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, Compact
GuardLogix 5380, and GuardLogix 5580 controllers.
Transfer data between function blocks when they are:
•Far apart on the same sheet.
•On different sheets within the same routine.
Output wire connector (OCON) and an input wire connector (ICON)
Disperse data to several points in the routine
Single output wire connector (OCON) and multiple input wire connectors (ICON)
Each function block uses a tag to store configuration and status information
about the instruction.
•The Logix Designer application automatically creates a tag for each
new function block instruction. Use this tag, rename the tag, or assign
a different tag.
•For IREFs and OREFs, create a tag or assign an existing tag.
Choose the function block
elements
Choose a tag name for an
element

Chapter 1 Program a Function Block Diagram
Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 13
For a:
Specify:
Tag
tag_name
Bit number ofa larger data type
tag_name.bit_number
Member of a structure
tag_name.member_name
Element of a one dimension array
tag_name[x]
Element of a two dimension array
tag_name[x,y]
Element of a three dimension array
tag_name[x,y,z]
Element of an array within a structure
tag_name.member_name[x]
Member of an element of an array
tag_name[x,y,z].member_name
where:
x is the location of the element in the first dimension.
y is the location of the element in the second dimension.
z is the location of the element in the third dimension.
For a structure within a structure, add an additional member_name.
Define execution order (flow of data) by wiring elements together and
indicating any input (feedback) wires, if necessary. The location of a block
does not affect the order in which the blocks execute.
When an IREF specifies input data for a function block instruction, the data
in that IREF is latched for the scan of the function block routine. The IREF
latches data from program-scoped and controller-scoped tags. The controller
updates all IREF data at the beginning of each scan as shown in this diagram.
In this example, the value of tagA is stored at the beginning of the execution
of the routine. The stored value is used when Block_01executes. The same
stored value is also used when Block_02 executes. If the value of tagA changes
Define the order of
execution
Data latching

Chapter 1 Program a Function Block Diagram
14 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
during execution of the routine, the stored value of tagA in the IREF does not
change until the next execution of the routine.
This example is the same as the previous example. The value of tagA is stored
only once at the beginning of the execution of the routine. The routine uses
this stored value throughout the routine.
With version 11 and later of the application, use the same tag in multiple
IREFs and an OREF in the same routine. Because the values of tags in IREFs
are latched every scan through the routine, all IREFs use the same value, even
if an OREF obtains a different tag value during execution of the routine. In
this example, if tagA has a value of 25.4 when the routine starts executing this
scan, and Block_01 changes the value of tagA to 50.9, the second IREF wired
into Block_02 still uses a value of 25.4 when Block_02 executes this scan.

Chapter 1 Program a Function Block Diagram
Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 15
The new tagA value of 50.9 is not used by any IREFs in this routine until the
start of the next scan.
The Logix Designer application automatically determines the order of
execution for the function blocks in a routine when:
•Verifying a function block routine.
•Verifying a project that contains a function block routine.
•Downloading a project that contains a function block routine.
Define the order of execution by wiring function blocks together and
indicating the data flow of any feedback wires, if necessary.
If function blocks are not wired together, it does not matter which block
executes first. There is no data flow between the blocks.
If the blocks are wired sequentially, the order of execution moves from input
to output. The inputs of a block require data to be available before the
controller can execute that block. In this example, block 2 has to execute
before block 3 because the outputs of block 2 feed the inputs of block 3.
Order of execution

Chapter 1 Program a Function Block Diagram
16 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
The order of execution is only relative to the blocks that are wired together.
The two groups of blocks in this example are not wired together. The blocks
within a specific group execute in the appropriate order in relation to the
blocks in that group.
To create a feedback loop around a block, wire an output pin of the block to an
input pin of the same block. In this example, the loop contains only a single
block, so execution order does not matter.
If a group of blocks are in a loop, the controller cannotdetermine which block
to execute first, and it cannot resolve the loop, as illustrated in this example.
To identify which block to execute first, mark the input wire that creates the
loop (the feedback wire) with the AssumeData Available indicator. In this
example, block 1 uses the output from block 3 that was produced in the
previous execution of the routine.
The Assume Data Available indicator defines the data flow within the loop.
The arrow indicates that the data serves as input to the first block in the loop.
Do not mark all the wires of a loop with the Assume Data Available indicator.
Resolve a loop

Chapter 1 Program a Function Block Diagram
Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 17
This example is OK.
This example is not OK.
The
Assume Data Available
indicator defines the data flow within the loop.
The controller cannot resolve the loop because all the wires use the
Assume Data
Available
indicator.
When using two or more wires to connect two blocks, use the same data flow
indicators for all of the wires between the two blocks.
This is OK
This is NOT OK
In this example, neither wire uses the Assume Data Available indicator.
In this example, both wires use the
Assume Data Available
indicator.
In this example, only one wire uses the Assume Data Availableindicator.
Use the Assume Data Available indicator to produce a one scan delay between
blocks. In this example, block 1 executes first. It uses the output from block 2
that was produced in the previous scan of the routine.
Resolve data flow between
two blocks
Create a one scan delay

Chapter 1 Program a Function Block Diagram
18 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
A function block routine executes in this order.
1. The controller latches all data values in IREFs.
2. The controller executes the other function blocks in the order
determined by how they are wired.
3. The controller writes outputs in OREFs.
Like wires, connectors transfer data from output pins to input pins. Use
connectors when:
•The elements to connect are on different sheets within the same
routine.
•A wire is difficult to route around other wires or elements.
•Data should be dispersed to several points in the routine.
To use connectors, use these rules.
•Each OCON requires a unique name.
•Each OCON must have at least one corresponding ICON, such as an
ICON with the same name as the OCON.
•Multiple ICONs can reference the same OCON. This allows dispersal of
data to several points in a routine.
These instructions support the concept of Program/Operator control.
•Enhanced Select (ESEL)
•Totalizer (TOT)
•Enhanced PID (PIDE)
•Ramp/Soak (RMPS)
•Discrete 2-State Device (D2SD)
•Discrete 3-State Device (D3SD)
Program/Operator control allows simultaneous control of these instructions
from the user program and from an operator interface device. When in
Program control, the instruction is controlled by the Program inputs to the
instruction. When in Operator control, the instruction is controlled by the
Operator inputs to the instruction.
Program or Operator control is determined by using these inputs:
Summary
Identify any connectors
Define program/operator
control

Chapter 1 Program a Function Block Diagram
Rockwell Automation Publication 1756-PM009J-EN-P - March 2022 19
Input
Description
.ProgProgReq
A program request to go to Program control.
.ProgOperReq
A program request to go to Operator control.
.OperProgReq
An operator request to go to Program control.
.OperOperReq
An operator request to go to Operator control.
To determine whether an instruction is in Program or Operator control,
examine the ProgOper output. If ProgOper bit is set, the instruction is in
Program control. If ProgOper bit is cleared, the instruction is in
Operator control.
Operator control takes precedence over Program control if both input request
bits are set. For example, if ProgProgReq and ProgOperReq bits are set, the
instruction goes to Operator control.
The Program request inputstake precedence over the Operator request
inputs. This provides the capability to use the ProgProgReq and ProgOperReq
inputs to lock an instruction in a desired control.
For example, assume that a Totalizer instruction is always used in Operator
control, and the user program never controls the running or stopping of the
Totalizer. In this case, wire a literal value of 1 into the ProgOperReq input.
This prevents the operator from ever putting the Totalizer into Program
control by setting the OperProgReq input from an operator interface device.

Chapter 1 Program a Function Block Diagram
20 Rockwell Automation Publication 1756-PM009J-EN-P - March 2022
Likewise, constantly setting the ProgProgReq input can "lock" the instruction
into Program control. This is useful for automatic startup sequences when the
program should control the action of the instruction without an operator
inadvertently taking control of the instruction. In this example, the program
sets the ProgProgReq input during the startup, and clears the ProgProgReq
input once the startup is complete. Once the ProgProgReq input is cleared,
the instruction remains in Program control until it receives a request to
change. For example, the operator sets the OperOperReq input from a
faceplate to take control of that instruction. This example shows how to lock
an instruction into Program control.
Operator request inputs to an instruction are always cleared by the
instruction when it executes. This lets operator interface work with these
instructions by setting the desired mode request bit. It is not necessary to
program the operator interface to reset the request bits. For example, if an
operator interface sets the OperAutoReq input to a PIDE instruction, when
the PIDE instruction executes, it determines the appropriate response and
clears the OperAutoReq.
Program request inputs are not normally cleared by the instruction because
these are normally wired as inputs into the instruction. If the instruction
clears these inputs, the input would get set again by the wired input. In some
situations, other logic should set the Program requests to be cleared by the
instruction. In this case, set the ProgValueReset input and the instruction
always clears the Program mode request inputs when it executes.