Mirus Communication Errors on Power Up with HM800

30 Jan 2023


"CAN errors detected. Ensure terminators are present," "Failed to communicate...," or similar error message.


These errors are generally caused by turning on the power to the HM800 console before plugging the USB cable into the tablet or from powering on the console before turning on the tablet and booting to the Windows desktop.


To prevent these errors from occurring, follow this procedure: 

  1. Dock the tablet or connect the USB cable.
  2. Boot the tablet to the Windows desktop.
  3. Turn on the power to the console.
  4. Open Mirus.

Additional Troubleshooting Steps:

Please follow the outlined steps:

  1. The next time you receive this error message, immediately open the Health diagnostic screen.
  2. Are there “Error Counts” on any of the three modules listed? If there are, is the number of errors counting down towards zero? If so, then watch the errors go to zero and then make sure the errors never go in the positive direction.

You should see a screen similar to this:


If the errors stay at zero, there is a good chance that the “CAN ERRORS” you are experiencing have to do with the power up sequence. Mirus was designed to buffer CAN ERRORS and then notify the user when these errors exceed a certain threshold. This is a feature that was added to the software with Mirus 3.1 and later. The most common cause of CAN ERRORS is powering the console ON before connecting the USB cable to the tablet (or the console is turned on before the tablet). To prevent these errors from occurring on power up, be sure to connect the USB cable to the tablet and boot the tablet to the Windows desktop before turning the power to the console ON.

Important Note

If, at any time, errors occur while in Mirus or anytime during harvest on an HM800 GrainGage, you should check to ensure there are two CAN terminators (no more than two) installed.  One should be inserted into one of the 4-ports of the splitter box located closest to the HM800 console and one inserted into one of the 4-ports of the splitter box located inside or by the weigh system. Either a missing terminator or an extra terminator can cause communication errors.

These CAN terminators look like a rubber plug that is about 3-5 cm long. The other three ports should have CAN cables attached. Make sure each of these cables are connected securely. All the connectors have a ¼ turn lock collar on them too. After plugging the cables into the mating connector, turn this collar clockwise ¼ turn until you feel it lock into place.  

If you are still having issues, please contact one of our HarvestMaster Field Service Engineers: