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Drive Communication Fault

Description of Fault

The CATALYST Drive utilizes a MODBUS serial communications terminal to communicate to the CATALYST controller. This is how run commands, fan status, speed control, and monitoring information such as power and faults is shared. If for any reason this communication is interrupted, the CATALYST will issue a Drive Communication fault.

The drive will display CALL or CE during a “Drive Communications Alarm. The alarm is automatically reset as soon as communications have been restored.

Possible Causes

A CATALYST Drive Communications Fault is typically caused by:

  • Drive parameters have not been entered, or have been entered incorrectly.

  • Drive has not had its power cycled after the parameters have been set.

  • An issue with wiring between the CATALYST controller and drive.


eIQ Platform

  1. A Drive Communication Fault is most commonly found during the installation process.

  2. If the fault occurs after the CATALYST has been installed and running properly, there is more than likely a physical issue with the wire.

  3. We recommend calling TW so that we can verify there are no software issues, and then a trained technician should be scheduled to visit the site.



  1. Verify the CATALYST controller has power.

  2. Verify all parameters are set correctly via the drives “Modified Constants” selection. This highlights all the parameters that have been modified.
    ***After all parameters have been set the power MUST be shut off for at least 30 seconds so the drive can fully power off. This puts the parameters into effect.

  3. Verify the wiring matches the wiring diagram and that there are no stray pieces of copper that are touching.

  4. Verify the connection on the MODBUS wire on the CATALYST controller is secure and that the terminal has not fallen off during shipping.

  5. Verify that the communication wire does not run parallel with high voltage wire. This can cause interference.

  6. If none of the above resolve the issue, contact Transformative Wave for further assistance at or (855) 867-2333.

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