OperReqInv (Status.4)

D3SD Multiple Operator State Requests

Allen-Bradley · Logix 5000 Advanced Process Control and Drives

What does OperReqInv (Status.4) mean?

The D3SD instruction received simultaneous requests from multiple operator state bits. This creates a conflict, making it impossible for the instruction to determine the intended operator command.

Common Causes

  • Multiple OperReq inputs (e.g., Oper0Req, Oper1Req) are active concurrently, indicating conflicting operator requests.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Review the operator interface and associated logic for the D3SD instruction — confirm that only one operator state request bit can be active at any given time, as described in the 'Commanded State in Program Control' section.

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Verified technical data. Last updated: March 2026

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Source: Allen-Bradley Logix 5000 Advanced Process Control and Drives