Troubleshooting Arc Roaster (multi barrel lab roaster)

In this article you will learn to troubleshoot the connection to a Multi Barrel Arc Roaster machine to Cropster Roasting Intelligence.

No Sources connected / No temperature readouts

Connecting the USB cable of an Arc Roaster's barrel to a different port in the computer may reassign (or rename) the Serial port. Because of the serial port reassignment, the Roasting Intelligence (RI) cannot load the serial port saved prior because it has changed, leading to No sources connected.

Select the serial port again on the RI instance where you do not have temperatures from; go to the Machine preferences to re-establish the connection. We recommend to identify the serial port.

Identifying the serial port

Multi barrel Arc Roasters have a Serial port for each barrel you are connecting to the computer. If you would like to ensure that you have linked the machine's barrel(s) to the correct instance of the RI, we recommend to identify the serial port referring to each of the machine's barrels.

  1. Go to Account > Preferences > Machine tab.
  2. Under Machine, take note of the barrel selected (e.g. Arc Roaster Barrel 1).
  3. Verify that the option Arc Roaster is selected from the drop-down for all measurements.
  4. Click on the gear () icon to open the PID-settings. 
  5. Click on the Serial port drop-down menu.
    Take note of the serial port options that appear e.g. COM3, and COM5.
    The serial ports available from the above picture were taken on a Windows computer, and may differ on your computer.
  6. Refer to the Barrel selected from the Machine field (e.g. Arc Roaster Barrel 1) and disconnect the USB cable corresponding to the barrel.

    If you've selected Barrel 1, undo the physical USB connection for the Arc Roaster's Barrel 1.
  7. Click the Update button, then check the Serial port options again.

The serial port referring to the disconnected barrel does not display anymore. e.g. if serial port COM3 disappears, then COM3 is the serial port referring to Arc Roaster Barrel 1.

Continue with Selecting the serial port.

Selecting the Serial port

  1. Reconnect the barrel's USB cable to the computer, and click the Update button.
  2. Select the Serial port option referring to the barrel's connection.
    If you haven't already, identify the serial port.
  3. Click Save to confirm the changes. The RI instance requires a restart to apply the settings.

Repeat the steps from the top to identify the serial port for more of your machine's barrels.


For further assistance, please create a support ticket by clicking the Support button in the left lower corner of the app. A Cropster support rep will get in touch with you.


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Check out our Getting started video and enjoy tracking your first roasts! 

More manuals and videos can be found on help.cropster.com.