Allen-Bradley LOGIX 5000 Reference Manual page 503

Function Block Attributes
Input
.ProgProgReq
.ProgOperReq
.OperProgReq
.OperOperReq
To determine whether an instruction is in Program or Operator control, examine
the ProgOper output. If ProgOper is set, the instruction is in Program control; if
ProgOper is cleared, the instruction is in Operator control.
Operator control takes precedence over Program control if both input request bits
are set. For example, if ProgProgReq and ProgOperReq are both set, the
instruction goes to Operator control.
The Program request inputs take precedence over the Operator request inputs.
This provides the capability to use the ProgProgReq and ProgOperReq inputs to
'lock' an instruction in a desired control.
For example, let's assume that a Totalizer instruction will always be used in
Operator control, and your user program will never control the running or
stopping of the Totalizer. In this case, you could wire a literal value of 1 into the
ProgOperReq. This would prevent the operator from ever putting the Totalizer
into Program control by setting the OperProgReq from an operator interface
device.
Likewise, constantly setting the ProgProgReq can 'lock' the instruction into
Program control. This is useful for automatic startup sequences when you want
the program to control the action of the instruction without worrying about an
operator inadvertently taking control of the instruction.
In this example, you have the program set the ProgProgReq input during the
startup, and then clear the ProgProgReq input once the startup was complete.
Once the ProgProgReq input is cleared, the instruction remains in Program
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
Description
A program request to go to Program control.
A program request to go to Operator control.
An operator request to go to Program control.
An operator request to go to Operator control.
Chapter 9
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