Allen-Bradley LOGIX 5000 User Manual

Equipment Phase Instructions
Chapter 7
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018 445
Structured Text
The operands are the same as those for the Ladder Diagram PFL instruction.
Guidelines for using the PFL Instruction
Guideline Details
Put the PFL
instruction in the
equipment
phase.
The PFL instruction sets the failure code for the equipment phase in which the instruction is put. There
is no operand to identify a specific equipment phase.
Typically, put the PFL instruction in a prestate routine for the equipment phase.
• The controller always scans the prestate routine, even when an equipment phase is in the idle
state.
• The controller scans the prestate routine before each scan of a state.
Number Description
Prestate routine
Current state routine
Use the progress routine to continuously monitor the health of an equipment phase as it progresses
through its states.
Prioritize failure
codes.
The PFL instruction sets the failure code only to a value greater than its current value.
• For example, if a PFL instruction sets the failure code = 102, another PFL instruction can only set
the failure code > 102.
• Make sure to assign higher values to exceptions that require higher priority in their handling.
Otherwise, a lower priority exception may overwrite a more critical exception.

Allen-Bradley LOGIX 5000 Specifications

General

Brand	Allen-Bradley
Model	LOGIX 5000
Category	Controller
Language	English