Cause : Analogue input signal lost comes when drive isn't receiving the expected analogue input signal, typically a 0-10V DC signal, that you're using to control motor speed, torque, or another parameter.

The F0080 fault code on a Siemens Micromaster 420 (MM420) indicates an analog input lost signal fault. This typically occurs when the drive is configured to receive an analog input signal from an external device (such as a potentiometer or another controller) and does not receive a valid signal.

Here are steps to diagnose and resolve this issue:

1. Check Analog Input Connection:

   • Verify the connection between the external analog signal source and the drive's analog input terminal. Ensure that the connections are secure and properly terminated.

2. Inspect Signal Source:

   • Check the analog signal source (e.g., potentiometer, PLC output) to ensure it is operational and sending the correct signal within the expected voltage range specified by the drive.

3. Verify Wiring:

   • Ensure that the wiring from the analog signal source to the drive is intact and correctly connected according to the drive's specifications. Check for any loose or damaged wires.

4. Analog Input Configuration:

   • Review the drive's parameter settings related to the analog input. Ensure that the input type (voltage or current), scaling, and range settings match the characteristics of the analog signal source.