Troubleshooting Arc Roasters (multi barrel)

In this article, you will learn to troubleshoot the USB connection for a multi barrel, Arc roast machine, to Cropster's Roasting Intelligence.

No Sources connected / No temperature readouts

Connecting the USB cable from one of the roast machine's barrels to a different port in the computer, may reassign/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.

To address the issue, and communicate with the serial port once more, select the serial port referring to the connection of the barrel, from the RI instance where you do not have temperatures. 

If you are unsure, which serial port refers to which barrel from the roast machine, we recommend identifying the serial port.

Identifying the serial port

USB-connected multi barrel roast machines, have a serial port for each barrel, that can connect to a computer.

If you would like to ensure that you have linked the machine's barrel(s) to the correct instances of the RI, we recommend identifying 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 Roasters, 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.


Thank you for being a Cropster customer!

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

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