Phase State Complete (PSC)

This instruction applies to the Compact GuardLogix 5370 and Compact GuardLogix 5380, CompactLogix 5370, CompactLogix 5380, and CompactLogix 5480, ControlLogix 5570 and ControlLogix 5580, and GuardLogix 5570 and GuardLogix 5580 controllers.
TIP:
When using this instruction with ControlLogix redundancy system, outputs controlled by this instruction may not be bumpless during redundancy switchover, if the instruction and phase program are not scheduled in the highest priority task.
Use the PSC instruction to signal an equipment phase that the state routine is complete to indicate that it should go to the next state.
The PSC instruction signals the completion of a phase state routine.
PSC DescriptionV32
In the running state routine, use the PSC instruction to transition the equipment phase to the complete state.
  • This is a transitional instruction. Follow these steps when using it:
    • In ladder logic, insert an instruction to toggle the rung-condition-in from false to true each time the instruction should execute.
    • In a Structured Text routine, insert a condition for the instruction to cause it to execute only on a transition.
Available Languages
Ladder Diagram
PSC_LD_avail_v31
Function Block
This instruction is not available in function block.
Structured Text
PSC( );
Operands
Ladder Diagram
None
Structured Text
None
Enter the parentheses ( ) after the instruction mnemonic, even though there are no operands.
Guidelines for using the PSC Instruction
Guideline
Details
Use the PSC instruction in
each
phase state routine that is added to an equipment phase.
Without a PSC instruction, the equipment phase remains in the state and does
not
 go to the next state.
  • Place the PSC instruction as the last step in the phase state routine.
  • When the state is done (complete), execute the PSC instruction.
PSC Holding Statev32
In the holding state routine, use the PSC instruction to let the equipment phase go to the Held state
Remember that the PSC instruction does
not
stop the current scan of a routine.
When the PSC instruction executes, the controller scans the rest of the routine and then transitions the equipment phase to the next state. The PSC instruction does not terminate the execution of the routine.
Do
not
use a PSC instruction in a prestate routine.
Use the PSC instruction only to signal the transition from one state to another.
Affects Math Status Flags
No
Major/Minor Faults
A major fault will occur if:
Fault type
Fault code
Instruction is called from outside an equipment phase program.
4
91
If an Add-On Instruction used a PSC instruction and a non-equipment phase program calls the Add-On Instruction,
Logix Designer
 gives a warning. Check the Add-On Instruction for this instruction and disallow it. See
Index Through Arrays
 for operand-related faults.
Execution
In structured text, instructions execute each time they are scanned. To limit the scan of an instruction, use a qualifier of an SFC action, a structured text construct, or both.
Condition/State
Action Taken
Prescan
No action taken.
Postscan
No action taken.
EnableIn is false
No action taken.
EnableIn is true
The instruction executes.
Examples
Ladder Diagram
PSC_LD_ex_v31
Structured Text
If TagEnableRunning
And PSCTest.Running Then
PSC();
End_if;
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