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Allen-Bradley LOGIX 5000 User Manual

Allen-Bradley LOGIX 5000
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Function Block Attributes
Chapter 9
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018 499
2. The controller executes the other function blocks in the order determined
by how they are wired.
3. The controller writes outputs in OREFs.
These process control and drives instructions support different timing modes.
DEDT
LDLG
RLIM
DERV
LPF
SCRV
HPF
NTCH
SOC
INTG
PI
TOT
LDL2
PIDE
There are three different timing modes.
Timing Mode Description
Periodic Periodic mode is the default mode and is suitable for most control applications. We recommend
that you place the instructions that use this mode in a routine that executes in a periodic task. The
delta time (DeltaT) for the instruction is determined as follows:
If the instruction executes in a Then DeltaT equals
Periodic task Period of the task
Event or continuous task Elapsed time since the previous execution
The controller truncates the elapsed time to whole
milliseconds (ms). For example, if the elapsed time =
10.5 ms, the controller sets DeltaT = 10 ms.
The update of the process input needs to be synchronized with the execution of the task or
sampled 5-10 times faster than the task executes in order to minimize the sampling error between
the input and the instruction.
Oversample In oversample mode, the delta time (DeltaT) used by the instruction is the value written into the
OversampleDT parameter of the instruction. If the process input has a time stamp value, use the
real time sampling mode instead.
Add logic to your program to control when the instruction executes. For example, you can use a
timer set to the OversampleDeltaT value to control the execution by using the EnableIn input of
the instruction.
The process input needs to be sampled 5-10 times faster than the instruction is executed in order
to minimize the sampling error between the input and the instruction.
Real time sampling In the real time sampling mode, the delta time (DeltaT) used by the instruction is the difference
between two time stamp values that correspond to the updates of the process input. Use this
mode when the process input has a time stamp associated with its updates and you need precise
coordination.
The time stamp value is read from the tag name entered for the RTSTimeStamp parameter of the
instruction. Normally this tag name is a parameter on the input module associated with the
process input.
The instruction compares the configured RTSTime value (expected update period) against the
calculated DeltaT to determine if every update of the process input is being read by the instruction.
If DeltaT is not within 1 millisecond of the configuration time, the instruction sets the RTSMissed
status bit to indicate that a problem exists reading updates for the input on the module.
Time-based instructions require a constant value for DeltaT in order for the
control algorithm to properly calculate the process output. If DeltaT varies, a
Timing Modes

Table of Contents

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Allen-Bradley LOGIX 5000 Specifications

General IconGeneral
Controller TypeProgrammable Automation Controller (PAC)
Communication ProtocolsEtherNet/IP, ControlNet, DeviceNet
Programming SoftwareStudio 5000
Programming LanguagesLadder Logic, Structured Text, Function Block Diagram, Sequential Function Chart
Supported I/OAnalog
Power Supply24V DC, 120/240V AC (depending on module)
Operating Temperature0°C to 60°C (32°F to 140°F)
Relative Humidity5% to 95% non-condensing
RedundancySupported with specific modules and configurations
CertificationsUL, CE

Summary

Important user information

Global changes

Details on global changes made in this release of the manual.

New or enhanced features

Information on new and updated features introduced in this manual.

Preface

Studio 5000 environment

Describes the Studio 5000 Automation Engineering & Design Environment.

Additional resources

Lists documents containing additional information on Rockwell Automation products.

Purpose of this manual

Explains the manual provides details on available instructions and guidance for equipment phase instructions.

Legal Notices

Contains copyright notice, End User License Agreement (EULA), and open source licenses.

Chapter 1 Process Control Instructions

Alarm (ALM)

Provides alarming for any analog signal.

Discrete 3-State Device (D3SD)

Controls discrete devices with three possible states (e.g., fast/slow/off).

Discrete 2-State Device (D2SD)

Controls discrete devices with two possible states (e.g., on/off).

Deadtime (DEDT)

Performs a delay of a single input with selectable deadtime.

Function Generator (FGEN)

Converts input based on a piece-wise linear function.

Lead-Lag (LDLG)

Provides phase lead-lag compensation for an input signal.

Enhanced PID (PIDE)

Provides enhanced capabilities over standard PID with velocity form algorithm.

Position Proportional (POSP)

Opens or closes device by pulsing contacts with pulse width proportional to position difference.

Ramp/Soak (RMPS)

Provides alternating ramp and soak periods to follow a temperature profile.

Scale (SCL)

Converts unscaled input to floating point value in engineering units.

Split Range Time Proportional (SRTP)

Drives heating/cooling digital outputs with periodic pulses based on PID output.

Totalizer (TOT)

Provides time-scaled accumulation of an analog input value.

Coordinated Control (CC)

Controls a single process variable by manipulating up to three control variables.

Internal Model Control (IMC)

Controls a single process variable using an internal model and compared error signal.

Modular Multivariable Control (MMC)

Controls two process variables using up to three control variables.

Chapter 2 Drives Instructions

Integrator (INTG)

Implements an integral operation.

Proportional + Integral (PI)

Provides two methods of operation for proportional and integral gains.

Pulse Multiplier (PMUL)

Provides interface from position input module by computing input change from scan to scan.

S-Curve (SCRV)

Performs a ramp function with an added jerk rate.

Second-Order Controller (SOC)

Provides a gain term, first order lag, and second order lead.

Up/Down Accumulator (UPDN)

Adds and subtracts two inputs into an accumulated value.

HMI Button Control (HMIBC)

Enables operators to initiate machine control operations via PanelView 5500.

Chapter 3 Filter Instructions

Derivative (DERV)

Calculates the amount of change of a signal over time in per-second units.

High Pass Filter (HPF)

Provides a filter to attenuate input frequencies below the cutoff frequency.

Low Pass Filter (LPF)

Provides a filter to attenuate input frequencies above the cutoff frequency.

Notch Filter (NTCH)

Provides a filter to attenuate input frequencies at the notch frequency.

Second-Order Lead Lag (LDL2)

Provides a filter with a pole pair and a zero pair.

Chapter 4 Select_Limit Instructions

Enhanced Select (ESEL)

Lets you select one of as many as six inputs based on selection options.

High/Low Limit (HLL)

Limits an analog input between two values (high/low, high, or low limits).

Multiplexer (MUX)

Selects one of eight inputs based on the selector input.

Rate Limiter (RLIM)

Limits the amount of change of a signal over time.

Select (SEL)

Uses a digital input to select one of two inputs.

Selected Negate (SNEG)

Uses a digital input to select between the input value and its negative.

Selected Summer (SSUM)

Uses Boolean inputs to select real inputs to be algebraically summed.

Chapter 5 Statistical Instructions

Moving Average (MAVE)

Calculates a time average value for the In signal, optionally supporting weights.

Maximum Capture (MAXC)

Retains the maximum value of the input over time and allows re-establishment of maximum.

Minimum Capture (MINC)

Retains the minimum value of the input over time and allows re-establishment of minimum.

Moving Standard Deviation (MSTD)

Calculates a moving standard deviation and average for the In signal.

Chapter 6 Logical and Move Instructions

D Flip-Flop (DFF)

Sets Q output to D input state on clock transition; QNot is opposite of Q.

JK Flip-Flop (JKFF)

Complements Q and QNot outputs when Clock input transitions from cleared to set.

Reset Dominant (RESD)

Uses Set and Reset inputs to control latched outputs; Reset has precedence.

Set Dominant (SETD)

Uses Set and Reset inputs to control latched outputs; Set has precedence.

Chapter 7 Equipment Phase Instructions

Attach to Equipment Phase (PATT)

Lets a program take ownership of an equipment phase.

Detach from Equipment Phase (PDET)

Relinquishes ownership of an equipment phase.

Equipment Phase Clear Failure (PCLF)

Clears the failure code of an equipment phase.

Equipment Phase Command (PCMD)

Transitions an equipment phase to the next state or sub state.

Equipment Phase External Request (PXRQ)

Initiates communication with FactoryTalk Batch software.

Equipment Phase Paused (PPD)

Sets up breakpoints within the logic of an equipment phase.

Equipment Phase New Parameters (PRNP)

Clears the NewInputParameters bit of an equipment phase.

Equipment Phase Override Command (POVR)

Gives a Hold, Stop, or Abort command to an equipment phase, regardless of ownership.

Chapter 10 Structured Text Programming

Structured Text Syntax

Explains statements, case sensitivity, tabs, and components like expressions and comments.

Structured Text Components: Comments

Details how to add comments using //, (* *), or /* */ formats.

Structured Text Components: Assignments

Explains using the assignment operator := to change values in tags.

Structured Text Components: Expressions

Describes how to use tag names, literals, functions, and operators in expressions.

Structured Text Components: Instructions

Explains how structured text statements can be instructions and their execution.

Structured Text Components: Constructs

Details program constructs like IF...THEN, CASE...OF, FOR...DO, WHILE...DO, REPEAT...UNTIL.

CASE...OF

Selects actions based on a numerical value using a case statement.

FOR...DO

Executes an action a number of times before doing anything else.

IF...THEN

Completes an action when specific conditions occur.

REPEAT...UNTIL

Continues performing an action until conditions are true.

WHILE_DO

Continues performing an action while certain conditions are true.

Chapter 11 Common Attributes for Advanced Process Control and Drives Instructions

Common Attributes

Guidelines for common attributes for Advanced Process Control and Drives Instructions.

Math Status Flags

Guidelines for Math Status Flags.

Immediate values

Details on entering immediate values in decimal or other radix.

Data Conversions

Rules for mixing data types in programming and operand conversions.

Elementary data types

Lists elementary data types supported by controllers and their ranges.

LINT data types

Describes the LINT data type as a 64-bit integer.

Floating Point Values

Explains REAL and LREAL tags, and IEEE 754 standard.

Index Through Arrays

Describes how to dynamically change array elements using tags or expressions.

Bit Addressing

Explains using bit addressing to access a particular bit within a container.

Function Block Faceplate Controls

Information on faceplate controls for function block instructions.

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