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
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.
Verified technical data. Last updated: March 2026
Related Faults
Source: Allen-Bradley Logix 5000 Advanced Process Control and Drives