Siemens Micromaster F0080 — What It Means
F0080 on a Siemens Micromaster 4 series drive indicates ADC lost input signal, also called analogue input lost signal. The drive expects an analog control signal (typically from a potentiometer, PLC analog output, or other transmitter) and either the signal is missing entirely, the wiring is broken, or the signal falls outside the acceptable range configured for that input. When the drive detects this loss, it trips on OFF2 and halts operation to prevent uncontrolled behavior.
This fault is not caused by a failed motor or power section. It points directly to the command input side of the system. The drive is looking for a valid setpoint and cannot find one, so your first job is to trace the analog signal from its source all the way to the drive terminals and confirm both the source and the path are working correctly.
Common Causes
- Broken wire or open circuit in analog input wiring A damaged cable, loose terminal, or break anywhere in the analog input path will cause the drive to lose the signal completely.
- Failed external analog source A potentiometer with a broken track, a dead PLC analog output module, or a transmitter that has stopped working will produce no valid command signal.
- Signal out of limits The analog input is present but falls outside the range the drive expects, so it rejects the signal and trips the fault.
- Incorrect parameter configuration The drive may be configured to expect an analog setpoint but is pointed at the wrong input terminal or the wrong signal type (voltage versus current).
- Loose or corroded terminal connections Poor contact at the analog input terminals on the drive or at the source can intermittently break the signal path.
Step-by-Step Fix
- Confirm the active control source in the drive parameters to verify the drive is actually supposed to use an analog input for its setpoint, not keypad or fieldbus control.
- Inspect the analog input wiring from the external source to the drive terminals, looking for broken conductors, loose screw terminals, damaged insulation, or poor shield connections.
- Measure the analog signal at the source using a multimeter to confirm the potentiometer, PLC output, or transmitter is producing the expected command voltage or current.
- Measure the signal at the drive input terminals to verify the command is reaching the inverter, if the source tests good but the drive still faults, the problem is in the wiring or termination.
- Check the input range and scaling configuration in the drive parameters to make sure the analog input type (voltage or current) and scaling match the device actually connected.
- Repair or replace the failed component by restoring wiring continuity, tightening terminals, replacing a bad potentiometer or transmitter, or correcting the parameter setup.
- Reset the fault after fixing the root cause by cycling drive power, using the BOP or AOP reset button, or triggering the configured digital input for fault reset.
Parts Often Needed
| Part | Notes |
|---|---|
| Analog input cable or wire | Amazon | Replace if continuity is lost or insulation is damaged, use shielded cable for low-voltage analog signals. |
| Potentiometer (speed control pot) | Amazon | Replace if the wiper track is broken or output is intermittent, match the resistance range to your drive configuration. |
| PLC analog output module | Amazon | Replace if the PLC output channel is dead and cannot produce the required command signal. |
When to Call a Pro
Call a qualified industrial electrician or controls technician if you are not familiar with measuring and troubleshooting low-voltage analog signals, if the fault persists after you have confirmed good wiring and a valid source signal, or if you need to modify drive parameters and are unsure of the correct control configuration. A technician with experience in Siemens Micromaster drives can quickly verify the parameter setup, test the analog input circuit with precision tools, and determine whether the issue is external wiring, a failed source device, or an internal drive problem that requires board-level repair or drive replacement.