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Tool board ID reading view

  • Before searching for the ID, use an XT30 cable to connect the tool board to the UTOC or a motherboard with bridge firmware flashed. Below is the reference wiring diagram.

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Power-off operation.

Before starting, completely turn off the printer and disconnect the power supply, and also disconnect any USB connections that may power the CAN nodes. Do not plug or unplug wiring harnesses, adjust the terminal resistors, or touch terminals while the power is on.

The “power-off measurement” here does not mean disconnecting the CAN wires. During measurement, the CAN wires and all nodes on the bus should remain connected in their normal operating configuration; otherwise, what is measured may only represent a single node or a single terminating resistor, which cannot represent the entire CAN bus.

Set the multimeter to the resistance range, and measure the resistance between CAN-H and CAN-L:

Reference ReadingJudgment and Handling
approximately 60Ω Normal, usually indicating that there is one at each physical end of the bus. 120Ω Terminal resistor
Approximately 120Ω Usually only one termination resistor is active; please enable the termination resistor at the other physical end according to the product wiring diagram.
Approximately 40Ω Usually three terminal resistors are active; please disable the redundant terminal resistors according to the product wiring diagram.

The above values are for reference only; multimeter accuracy, probe contact, and wiring harness condition can all cause measurement errors. The key to judgment is which range the reading is close to, as well as the trend of reading changes after adjusting the terminal resistor; it is not required to match the values in the table exactly.

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CANBus UUID Acquisition​

Preparation​

Important Prerequisites
  • Toolboard Status: Ensure the toolboard has been flashed with Klipper-can firmware or is in Katapult-can mode
  • Important Note: This tutorial is only for searching toolboard IDs, not for mainboard IDs
  • Connection Requirement: The toolboard must be connected to one of the following devices:
    • UTOC module
    • A mainboard flashed with USB Bridge CAN firmware
  • Power Requirement: Some mainboards cannot detect the toolboard when powered only through USB. Completely power off the machine first, then connect a supported 12V-24V low-voltage supply according to the mainboard documentation. Power it on again before searching for the toolboard ID
  • Final Connection: The above devices need to be connected to the host machine

CAN Network Configuration Requirements​

  • Default Configuration: This tutorial assumes the host machine has already configured the CAN network
  • Fly Users: If using a Fly host running the Fly-FAST system, CAN is configured by default (1Mbps rate)
  • First-time Use: Please be sure to read the tutorial below first: CAN Configuration Tutorial

Connecting via SSH​

  • Log in to SSH over the network (do not use serial login)
  • Ensure the host machine is properly connected to the CAN network devices

Searching for CAN ID​

  • Search command for standard host machines 
    ~/klippy-env/bin/python ~/klipper/scripts/canbus_query.py can0
  • Search command for FLY host machines 
    python3 ~/klipper/scripts/canbus_query.py can0

Explanation of Search Results​

CANID
  • Note: The mainboard ID has already been configured into Klipper in previous documentation, so the mainboard's CANID cannot normally be found during a search
  • Quick Verification Method: If confirmation is needed, first disconnect the CAN connection cable between the mainboard and the toolboard, then re-run the search
  • After executing the search command, the following situations may occur:
Result DisplayedStatus DescriptionNext Steps
Application: KlipperDevice has Klipper firmware flashedThe ID can be used directly
Application: CANBOOT or KatapultDevice is in Bootloader modeKlipper firmware must be flashed before use
Total 0 uuids foundNo devices foundPlease check the following issues:
1. Whether the CAN network configuration is correct
2. Whether the CAN baud rate is consistent (default 1Mbps)
3. Whether this ID is already in use in the configuration (if so, comment it out, save, power off, and restart)
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Regarding Duplicate IDs

If a device ID is already configured in printer.cfg, it will not appear in the search results. To search again, please:

  1. Comment out that device ID in the configuration file
  2. Save the configuration and restart Klipper
  3. Power off and restart all devices

Configuring the CAN Device ID​

1. Locate the Configuration File​

Based on the web interface being used, find the printer.cfg configuration file:

Fluidd
Click the {...} icon in the left navigation bar, then find printer.cfg

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Mainsail
Click Machine in the top navigation bar, then find printer.cfg

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2. Add Device Configuration​

Add the toolboard configuration to printer.cfg:

[mcu toolboard]
canbus_uuid: <fill in the queried ID here>
Configuration Notes
  • toolboard is the name of the toolboard; modify it according to the actual situation
  • For a mainboard ID, the configuration section should be [mcu]
  • In normal configurations, the mainboard uses [mcu], and the toolboard uses [mcu toolboard]

3. Save and Restart​

  1. Click the SAVE & RESTART button in the top right corner
  2. The system will automatically save the configuration and restart Klipper
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Note

All IDs appearing in this documentation are examples only; the actual IDs differ from board to board. Please modify and fill in the ID based on what you actually obtain.

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