Phase Override Command (POVR)
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 POVR instruction to give a Hold, Stop, or Abort command to an equipment phase, regardless of ownership.
The POVR instruction:
- Gives the Hold, Stop, or Abort command to an equipment phase.
- Overrides all owners of the equipment phase. The command works even ifLogix Designersoftware, HMI,FactoryTalk Batchsoftware, or another program already owns the equipment phase. This instruction does not change the ownership of the equipment phase.
- High priority HMI ownership is specific only toCompactLogix5370 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
POVR (PhaseName, Command, Result);
Operands
Ladder Diagram
Operand | Type | Format | Description |
---|---|---|---|
Phase Name | phase | Name of the equipment phase | Equipment phase to change to a different state |
Command | command | Name of the command | One of these commands for the equipment phase:
|
Result | DINT | immediate tag | To let the instruction return a code for its success or failure, enter a DINT tag in which to store the result code. Otherwise, enter 0. |
Structured Text
The operands are the same as those for the Ladder Diagram POVR instruction.
Guidelines for using the POVR Instruction
Guideline | Details |
---|---|
If want to override other owners. | Want the equipment to hold, stop, or abort even if have manual control of the equipment phase via Logix Designer software?
This also applies to HMI, FactoryTalk Batch software or other programs. Use the POVR only to hold, stop, or abort, regardless of ownership.For example, suppose the equipment checks for jammed material. If there is a jam, always abort the equipment. In that case, use the POVR instruction. This way, the equipment aborts even under manual control via Logix Designer 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, use methods such as:
|
POVR Result Codes
If assigning a tag to store the result of a POVR instruction, the instruction returns one of these codes when it executes:
Code (Dec) | Description |
---|---|
0 | Successful command. |
24577 | Invalid command. |
24578 | Invalid command 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 | Unscheduled or inhibited equipment phase or in an inhibited task. |
Affects Math Status Flags
No
Major/Minor Faults
None. See
Index Through Arrays
for operand-related faults. Execution
Condition/State | Action Taken |
---|---|
Prescan | No action taken. |
Postscan | No action taken. |
EnableIn is false | No action taken. |
EnableIn is true | The instruction executes. |
Example
Number | Description |
---|---|
The equipment program watches for the these faults:
If there is a fault, then Local_Interface.Equipment_Faults_Cleared = 0. This tag is an alias for the controller-scoped tag Shear_1 . | |
The prestate routine of the equipment phase watches for the equipment program to signal a fault.
If there is a fault, then Give the Shear_One_Phase equipment phase the abort command. The POVR instruction makes sure the command works, even if someone has manual control of the equipment phase through Logix Designer software.The PFL instruction sets the failure code for Shear_One_Phase = 333 .The Fault_Strobe keeps these actions to a single scan. |
Ladder Diagram
Example 2
Structured Text
If NOT Equipment_Faults_Cleared And NOT Fault_Strobe then
POVR(POVRTest,Abort, 0);
PFL(333);
end_if;
Fault_Strobe := NOT Equipment_Faults_Cleared;
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