Allen-Bradley LOGIX 5000 User Manual

Select_Limit Instructions
Chapter 4
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018 369
Execution
Function Block
Condition/State Action Taken
Prescan EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is false EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is true EnableIn and EnableOut bits are set to true
The instruction executes.
Instruction first run N/A
Instruction first scan Initialize Out with the value of In.
Postscan EnableIn and EnableOut bits are cleared to false.
Structured Text
Condition/State Action Taken
Prescan See Prescan in the Function Block table.
Normal Execution See Tag.EnableIn is true in the Function Block table.
Postscan See Postscan in the Function Block table.
Example
Function Block
The RLIM instruction limits In by IncRate. If analog_input1 changes at a rate
greater than the IncRate value, the instruction limits In. The instruction sets Out
= rate limited value of In.
Structured Text
RLIM_01.In := analog_input1;
RLIM_01.IncRate := value;
RLIM(RLIM_01);
rate_limited := RLIM_01.Out;
See also
Common Attributes on page 537
Structured Text Syntax on page 508

Allen-Bradley LOGIX 5000 Specifications

General

Brand	Allen-Bradley
Model	LOGIX 5000
Category	Controller
Language	English