No reference.

What does 156 mean?

The reference point for the drive is not known. In absolute positioning mode, homing was not performed before the first positioning command, which is essential for establishing a known position.

• Drive is operating in absolute positioning mode (e.g., Parameter C1210 = 1 for absolute) but has not completed a homing routine.
• The homing procedure was interrupted, failed (e.g., due to limit switch error), or did not successfully establish a valid reference.
• Encoder battery (for multi-turn absolute encoders) is depleted or disconnected, causing loss of position data on power cycle.
• Homing offset parameter (e.g., C1220) is incorrectly configured, leading to an invalid reference point.
• Memory corruption or parameter reset causing the loss of the stored reference point data.

Click steps to track your progress.

1. 1

   1. Initiate and complete a homing sequence as defined in the system's operational manual. Monitor homing status (e.g., P5-06 for 'Homing Done' bit).

2. 2

   2. For absolute encoders with battery backup, check the encoder battery voltage (if a diagnostic parameter exists) and replace if below specification (e.g., 3.0VDC).

3. 3

   3. Verify the homing mode (e.g., C1211) and homing offset (C1220) parameters are correctly configured for the application.

4. 4

   4. Cycle power to the drive and re-attempt homing to confirm persistent loss of reference.

5. 5

   5. Check the encoder cable and connections (e.g., X2 connector) for any intermittent faults that could cause loss of absolute position data.