Fagor alarm 5004: CAN bus error
Fagor CAN/remote I/O error · Fagor 8060/8065/8070
What it means
On CNC 8055 machines with remote RIO I/O expansion over the CAN bus, this error stops all axes and spindle, removes enables and fires the external emergency output. A sub-code identifies the fault: 2 = transmit queue full, 128 = Bus Off after repeated errors, 129 = warning state with more than 96 bus errors, 130 = messages lost or flooded, typically a wrong baud rate for the cable length, 131 = the CNC dropped into an inoperative bus state.
Likely causes
- broken or unplugged CAN cable between CNC and first node
- missing or faulty line terminating resistor driving the error counter up
- baud rate (g.m.p. IOCANSPE, P88) mismatched to actual cable length
- marginal node repeatedly resetting and polluting the bus
Triage note: Read the sub-code shown with the alarm before swapping parts: 130 points to speed/cable length, 128/129 point to physical layer (cable, terminators, shields).
Need the part urgently?
Send us alarm 5004 with your machine details — typical RFQ turnaround is 24–48h.