Video: What causes an HMI COM FAULT on an ATV61 or ATV71 series drive?


23 January 2021

HMI COM Fault causes on an ATV61 or ATV71.

Product Line:
ATV61 / ATV71 series drives

Where the HMI keypad is being used to control the start/stop of the drive and/or the speed reference: All models, All serial numbers.

Customer unable to find the answer in existing literature

HMI Com fault is caused when the HMI loses communication with the drive.   The HMI module of the ATV61/ATV71 series drives establishes a Modbus RTU connection at power up with the HMI being the Modbus Master.  This connection is separate from the Modbus/Canopen channel and is isolated.  This fault can only occur when the drive is configured to receive the start/stop control and/or the speed reference from the keypad.  

When this fault occurs, the most common causes are: 
- A failure of the HMI itself (part# VW3A1101)
- If the keypad is mounted remotely, the cable connecting it to the drive has failed. (VW3A1104RXX where XX = 10 for 1 meter cable, 30 for 3 meter, 50 for 5 meter or 100 for 10 meter)