Phase Clear Failure (PCLF)
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.
Use the PCLF instruction to clear the failure code of an equipment phase.
The PCLF instruction clears the failure code for an equipment phase.
- Use only a PCLF instruction to clear the failure code of an equipment phase.
- A CLR instruction, MOV instruction, or assignment (:=)does notchange the failure code of an equipment phase.
Make sure the equipment phase
does not
have other owners when using the PCLF instruction. The PCLF instruction will not
clear the failure code if Logix Designer
, HMI, FactoryTalk Batch
software, or another program owns the equipment phase.- High priority HMI ownership is specific only to theCompactLogix5370 andControlLogix5570 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.
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.
Ladder Diagram
Function Block
This instruction is not available in function block.
Structured Text
PCLF(Phase_Name);
Operands
Ladder Diagram
Operand | Type | Format | Description |
---|---|---|---|
Phase Name | PHASE | Name of the equipment phase | Equipment phase whose failure code to clear. |
Structured Text
The operands are the same as those for the Ladder Diagram PCLF instruction.
Affects Math Status Flags
No
Major/Minor Faults
None. See
Index Through Arrays
below for operand-related faults.Execution
For Structured Text, EnableIn is always true during normal scan. Therefore, if the instruction is in the control path activated by the logic, it executes.
Condition/State | Action Taken |
---|---|
Prescan | No action taken. |
Postscan | No action taken. |
EnableIn is false | No action taken. |
EnableIn is true | The instruction executes as described above. |
Example
Ladder Diagram
If
Drain_Tank_Restart
= 1 (restart the Drain_Tank
equipment phase) thenClear the failure code of the
Drain_Tank
equipment phaseChange the state of the
Drain_Tank
equipment phase to restarting via the restart command.Drain_Tank_Restart
= 0;Structured Text
(*If
Drain_Tank_Restart
= on, thenClear the failure code for the
Drain_Tank
equipment phase.Restart the
Drain_Tank
equipment phase.Turn off
Drain_Tank_Restart
.*)If
Drain_Tank_Restart
ThenPCLF(
Drain_Tank
);PCMD(
Drain_Tank
,Restart,0);Drain_Tank_Restart
:= 0;End_If;
Provide Feedback