Encoder Fault

What does 37 mean?

This fault indicates a problem with the motor encoder, which could be an overspeed condition, improper setup, or a general malfunction. Accurate encoder feedback is crucial for precise motor control and speed regulation, especially in closed-loop applications. Incorrect feedback can lead to unstable operation.

• Encoder feedback cable damaged, loose, or incorrectly wired to the drive's encoder input terminals (e.g., A, A/, B, B/, Z, Z/).
• Encoder power supply voltage (e.g., 5VDC or 24VDC) lost or outside tolerance (e.g., measuring <4.5VDC at encoder terminals).
• Encoder physical damage, contamination (e.g., dust on optical disk), or mechanical misalignment causing signal loss or erratic pulses.
• High electrical noise on encoder feedback lines due to inadequate shielding or proximity to power cables, causing false signals.
• Overspeed condition: motor speed exceeding the encoder's maximum rated RPM or the drive's configured speed limit (P1-09).

Click steps to track your progress.

1. 1

   1. Power down. Verify all encoder cable connections at both the encoder and drive (e.g., terminals 1-10 on the encoder board) are tight and correct according to the wiring diagram.

2. 2

   2. Measure the encoder supply voltage (e.g., +5VDC or +24VDC) at the encoder connector using a multimeter to ensure it is within specified limits.

3. 3

   3. Visually inspect the encoder unit for physical damage, debris, or misalignment on the motor shaft.

4. 4

   4. Using an oscilloscope, verify the A, A/, B, B/ channel signals for clean, square waveforms with appropriate voltage levels and phase relationship while the motor is slowly rotated.

5. 5

   5. Check parameter settings related to the encoder (e.g., P3-01 Encoder Pulses, P3-02 Encoder Type) ensuring they accurately match the installed encoder.