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| -rw-r--r-- | docs/CANBUS_Troubleshooting.md | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/docs/CANBUS_Troubleshooting.md b/docs/CANBUS_Troubleshooting.md index 6b7973ba..fdd33ca1 100644 --- a/docs/CANBUS_Troubleshooting.md +++ b/docs/CANBUS_Troubleshooting.md @@ -118,6 +118,23 @@ necessary to increase the `txqueuelen` above the recommended value of 128. However, as above, care should be taken when selecting a new value to avoid excessive round-trip-time latency. +## Use `canbus_query.py` only to identify nodes never previously seen + +It is only valid to use the +[`canbus_query.py` tool](CANBUS.md#finding-the-canbus_uuid-for-new-micro-controllers) +to identify micro-controllers that have never been previously +identified. Once all nodes on a bus are identified, record the +resulting uuids in the printer.cfg, and avoid running the tool +unnecessarily. + +The tool is implemented using a low-level mechanism that can cause +nodes to internally observe bus errors. These internal errors may +result in communication interruptions and may result is some nodes +disconnecting from the bus. + +It is not valid to use the tool to "ping" if a node is connected. Do +not run the tool during an active print. + ## Obtaining candump logs The CAN bus messages sent to and from the micro-controller are handled |