Siemens SINUMERIK 840D sl Series Diagnostics Manual page 714

Overview of Alarms
Cause: A CAN communications error has occurred.
Fault value (r0949, decimal):
1: The error counter for the send telegrams has exceeded the BUS OFF value 255. The
bus disables the CAN controller.
- bus cable interrupted.
- bus cable not connected.
- incorrect baud rate.
- incorrect bit timing.
2: The master no longer interrogated the CAN node status longer than for its "life time".
The "life time" is obtained from the "guard time" (p8604[0]) multiplied by the "life time
factor" (p8604[1]).
- bus cable interrupted.
- bus cable not connected.
- incorrect baud rate.
- incorrect bit timing.
- master fault.
Note:
The fault response can be set as required using p8641.
See also: p8641
Remedy: - check the bus cable
- check the baud rate (p8622).
- check the bit timing (p8623).
- check the master.
208701 <location>CBC: NMT state change
Reaction: A_INFEED: OFF2
SERVO: OFF3
Acknowledge: IMMEDIATELY
Cause: A CANopen NMT state transition from "operational" to "pre-operational" or after "stopped".
Fault value (r0949, decimal):
1: CANopen NMT state transition from "operational" to "pre-operational".
2: CANopen NMT state transition from "operational" to "stopped".
Note:
In the NMT state "pre-operational", process data cannot be transferred and in the NMT
state "stopped", no process data and no service data can be transferred.
Remedy: None necessary.
Acknowledge the fault and continue operation.
208751 <location>CBC: Telegram loss
Reaction: NONE
Acknowledge: NONE
Cause: The CAN controller has lost a receive message (telegram).
Remedy: Reduce the cycle times of the receive messages.
208752 <location>CBC: Error counter for error passive exceeded
Reaction: NONE
Acknowledge: NONE
Cause: The error counter for the send or receive telegrams has exceeded the value 127.
Remedy: - check the bus cable
- set a higher baud rate (p8622).
- check the bit timing and if required optimize (p8623).
208753 <location>CBC: Message buffer overflow
Reaction: NONE
Acknowledge: NONE
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SINUMERIK 840D sl/840D/840Di/810D Diagnostics Guide (DA), 08/2005 Edition
© Siemens AG, 2005. All rights reserved
08/2005