3174

Common Causes

• Loose, damaged, or disconnected servo link cable or connector
• Failed inverter unit control board
• Faulty FCP board
• Noise or marginal connection causing CRC/parity/time-out errors

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code bit 15 = Error in the 2nd B-buffer of the servo link; code bit 14 = Error in the 2nd A-buffer of the servo link; code bit 13 = Error in the 1st B-buffer of the servo link; code bit 12 = Error in the 1st A-buffer of the servo link; code bit 11 = MT buffer error; code bit 10 = Relay processing error on the link; code bit 9 = Data overrun in the receiving part of the interface; code bit 8 = Physical disconnection detected on the servo link
2. 2Read the alarm code on screen and decode the YYYY bit field: bit 8 set means a physical disconnection, bit 5 a CRC error, bit 0 a time-out, bits 12-15 buffer errors, bit 10 a relay processing error.
3. 3If bit 8 (disconnection) is set, power down and lock out, then inspect and reseat every servo link cable and connector between the FCP board and the inverter unit for the axis named in the object; look for bent pins, chafed cable, or oil contamination.
4. 4If CRC, parity, format, or time-out bits are set, check connector seating and cable routing away from power cables, since these point to noise or a marginal connection rather than a hard break.
5. 5Swap or test the servo link cable with a known-good one if available before condemning any boards.
6. 6If the cable and connectors check out, suspect the inverter unit control board for the reported axis, then the FCP board, in that order.
7. 7If the alarm returns after these checks, record the alarm number, the full XXXXYYYY code, and the axis object and contact Okuma service.