1174

Common Causes

• Loose, damaged or disconnected servo link cable/connector between the FCP board and inverter unit
• Faulty inverter unit control board
• Faulty FCP board
• Electrical noise or poor grounding corrupting link data (CRC/parity/format errors)

Troubleshooting Steps

1. 1Read the code number shown with the alarm: code bit 15 = 2nd B-buffer error; code bit 14 = 2nd A-buffer error; code bit 13 = 1st B-buffer error; code bit 12 = 1st A-buffer error; code bit 11 = MT buffer error; code bit 10 = Relay processing error; code bit 9 = Data over error in the interface receive section; code bit 8 = Disconnection on the servo link
2. 2Read the alarm code on screen and decode the YYYY bits: bit 0 = time-out, bit 1 = parity, bit 5 = CRC, bit 8 = disconnection, bit 9 = data over in the receive section; a disconnection or time-out bit points first at cabling, while CRC/parity/format bits point at noise or a board.
3. 3Power down and lock out the machine; reseat and inspect the servo link cables and connectors between the FCP board and the inverter unit for bent pins, contamination or damage.
4. 4Check cable routing and grounding/shielding for noise pickup if the code shows CRC, parity or format errors.
5. 5If cabling is good, substitute or have tested the inverter unit control board for the alarmed axis.
6. 6If the error persists, the FCP board is the remaining suspect; record the alarm number, full code and object and contact Okuma service.