Equipment Sequence Override (SOVR)

This instruction applies to the
Logix Designer
 5580 P-controllers. The
Logix Designer
 5580 P-controllers also support controller redundancy.
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 sequence program are not scheduled in the highest priority task.
WARNING:
When using redundancy with an
Equipment Sequence
, sequence execution may not be as expected after switchover if the phase and sequence are not scheduled on the same task.
Use the
Equipment Sequence
 Override (SOVR) instruction to send a HOLD, STOP, or ABORT command to an
Equipment Sequence
, regardless of ownership.
IMPORTANT:
The SOVR instruction is intended for emergencies only. Control Engineers should use caution when deciding to use it.
When a tag is assigned to store the result of an SOVR instruction, the instruction returns one of five result codes when it runs. Result code
0
 indicates that the SOVR instruction ran successfully. The other four codes indicate that the instruction did not run successfully and provide additional information about the reason for the instruction failure.
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
SOVR_LD_avail_v34
Function Block
This instruction is not available in function block.
Structured Text
SOVR(SequenceName, Sequence Command, Result)
Operands
Ladder Diagram
Operand
Data Type
Format
Description
Sequence Name
SEQUENCE
Name of the
Equipment Sequence
Equipment Sequence
 to perform the command.
Command
Command Enum
Name of the command
Command to send to the
Equipment Sequence
. Send one of these commands: HOLD, STOP, or ABORT
Result
DINT
Tag
For an instruction to return a success or failure code, enter a DINT tag where the result code is to be stored. Otherwise, enter 0.
Structured Text
The operands are the same as the Ladder Diagram.
Guidelines for using the SOVR Instruction
Guideline
Details
Make sure you want to override other owners.
Under most circumstances, use the SCMD instruction to programmatically command an
Equipment Sequence
. However, use the SOVR instruction to command an
Equipment Sequence
under these conditions:
  • When you are giving the HOLD, STOP, or ABORT command, and the command must always execute under all ownership circumstances.
  • If the HOLD, STOP, or ABORT command must execute even when you have manual control of the
    Equipment Sequence
     through the
    Logix Designer
     application or when another program, such as the
    FactoryTalk Batch
     software, owns the
    Equipment Sequence
    .
Limit execution of the SOVR instruction to a single scan.
Limit the execution of the SOVR instruction to a single scan. Each command applies to only a specific state or states. Once the
Equipment Sequence
 changes state, the command is no longer valid. To limit execution, use methods such as:
  • Run the SOVR instruction within a P1 Pulse (Rising Edge) or P0 Pulse (Falling Edge) action.
  • Place a one-shot instruction before the SOVR instruction.
  • Run the SOVR instruction and then advance to the next step.
Avoid making unnecessary command requests if the
Equipment Sequence
 is generating sequence events.
Unnecessary command requests can flood the event processing buffers and cause you to miss significant events.
SOVR Result Codes
Code (Desc)
Description
0
The command was successful.
24579
The caller is attached to this Sequence, but it is not the current Owner of it. A higher priority application is currently the Owner of this sequence.
24582
The caller already has override ownership of this Sequence.
24583
This sequence’s attachment table is full.
24606
The caller has already established an external attachment or override as a different owner type.
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Index Through Arrays[1] for operand related faults.
Execution
At instruction execution, the SOVR instruction attempts to command the specified
Equipment Sequence
.
Ladder Diagram
Condition
Action Taken
Prescan
No action taken
Rung-condition-in is false
No action taken
Rung-condition-in is true
The instruction executes.
Postscan
No action taken
Structured Text
Condition
Action Taken
Prescan
No action taken
Rung-condition-in is false
No action taken
Rung-condition-in is true
The instruction executes
Postscan
No action taken
Example
Ladder Diagram
SOVR_LD_Example_v34
Structured Text
if (OverrideControl) then
SOVR(Make_Product_101, Abort, Result);
end_if
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