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 if
    Logix Designer
     software, HMI,
    FactoryTalk Batch
     software, 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 to
    CompactLogix
     5370 and
    ControlLogix
     5570 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.
Available Languages
Ladder Diagram
POVR_LD_avail_v31
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:
  • Hold
  • Stop
  • Abort
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?
  • Yes - Use the POVR instruction
  • No - Use the PCMD instruction
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:
  • 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.
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
RSL5K_POVR Equipment Phase Override CommandV32
Number
Description
1
The equipment program watches for the these faults:
  • Faulted axis
  • Jammed material
If there is a fault, then
Local_Interface.Equipment_Faults_Cleared
 = 0. This tag is an alias for the controller-scoped tag
Shear_1
.
2
The prestate routine of the equipment phase watches for the equipment program to signal a fault.
  • If
    Interface_To_Equipment.Equipment_Faults_Cleared
    =0 then there is a fault.
  • Both
    Interface_To_Equipment
     and
    Local_Interface
     as aliases for
    Shear_1
    , so they have the same values.
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
POVR_LD_ex1_v31
Example 2
POVR_LD_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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