Rockwell Automation 1794-Lxxxx PhaseManager - Manual (Page 69)

Publication LOGIX-UM001B-EN-P - April 2010 69
Equipment Phase Instructions (PSC, PCMD, POVR, PFL, PCLF, PXRQ, PRNP, PPD, PATT, PDET) Appendix A
Guidelines for Using the POVR Instruction
POVR Result Codes
If you assign a tag to store the result of a POVR instruction, the instruction
returns one of the following codes when it executes:.
Arithmetic Status Flags: not affected
Fault Conditions: none
Guideline Details
Make sure you want to override other
owners. Do you want the equipment to hold, stop, or abort even if you have manual control of the
equipment phase via RSLogix 5000 software?
• YES — Use the POVR instruction.
• NO — Use the PCMD instruction.
This also applies to FactoryTalk Batch software or other programs. Use the POVR only when
you must hold, stop, or abort regardless of ownership.
Example: Suppose your equipment checks for jammed material. And if there is a jam, you
always want the equipment to abort. In that case, use the POVR instruction. This way, the
equipment aborts even if you have manual control via RSLogix 5000 software.
Limit execution of a POVR instruction
to a single scan. Limit the execution of the POVR instruction to a single scan. Each command applies to only a
specific state or states. Once the equipment phase changes state, the command is no longer
valid. To limit execution:
• execute the POVR instruction within a P1 Pulse (Rising Edge) or P0 Pulse (Falling Edge)
action.
• place a one shot instruction before the POVR instruction.
• execute the POVR instruction and then advance to the next step.
Code (Dec) Description
0 The command was successful.
24577 The command is not valid.
24578 The command is not valid for the current state of the equipment phase.
For example, if the equipment phase is in the stopping state, then a
hold command is not valid.
24594 The equipment phase is unscheduled, inhibited, or in a task that is
inhibited.