Allen-Bradley LOGIX 5000 User Manual

Process Control Instructions
Chapter 1
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018 65
When the value computed for the output becomes valid, the instruction initializes
the internal parameters and sets Out = (In x Gain) + Bias.
Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Common Attributes for operand-related
faults.
Execution
Function Block
Condition Function Block Action
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 Execute "Out = (In * Gain) + Bias".
Recalculate Lead/Lag coefficients.
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
The LDLG instruction in this example adds a first-order lag to a simulated
process. Optionally, you could enter a Gain on the LDLG instruction to simulate
a process gain, and you could enter a Bias to simulate an ambient condition.

Allen-Bradley LOGIX 5000 Specifications

General

Brand	Allen-Bradley
Model	LOGIX 5000
Category	Controller
Language	English