PI Feedback Loss Fault
Yaskawa · E7 Drive
Was bedeutet PIFB-FL ?
This fault occurs when the PI function's feedback signal is determined to be lost, as configured by parameter b5-12 set to '2: Fault'. Upon detection, the drive will coast to a stop and energize the fault output (MA-MB), indicating a critical loss of process control feedback that requires immediate attention.
Häufige Ursachen
- Failure of the PI feedback sensor (e.g., pressure transducer, flow meter) connected to the drive's analog input.
- Open circuit or high resistance in the feedback signal wiring between the sensor and drive analog input terminal (e.g., A1, A2, AC).
- Incorrect configuration of PI feedback parameters, such as b5-04 (Feedback Input Selection) or b5-05 (Feedback Gain).
- Feedback signal level consistently below the PI Feedback Loss Detection Level (b5-13) for the set detection time.
- External electromagnetic interference (EMI) or ground loop issues corrupting the low-level analog feedback signal.
Reparaturschritte & Checkliste
Klicken Sie auf Schritte, um Ihren Fortschritt zu verfolgen.
- 1
Measure the analog output signal directly at the feedback sensor terminals to confirm it is producing a valid range (e.g., 4-20mA, 0-10VDC).
- 2
Verify continuity and insulation integrity of the feedback signal wiring between the sensor and the drive's analog input terminals (e.g., A1-AC) using a multimeter.
- 3
Confirm parameter b5-04 (Feedback Input Selection) matches the connected analog input terminal and b5-12 is set to '2' (Fault).
- 4
Adjust parameter b5-13 (PI Feedback Loss Detection Level) to be appropriately low, just above the expected zero signal noise floor.
- 5
Apply a known test signal (e.g., from a signal generator) to the drive's analog input terminals to verify the drive correctly processes the feedback.
- 6
Inspect for proper shielding and grounding of the feedback signal cable, ensuring it is separated from power cables.