Applicable Systems
Modicon M221
Modicon M241
Modicon M251
Modicon M340
Modicon M580
Altivar
Symptoms
4-20mA reference signal lost.
Possible Causes
- Signal cable broken
- Sensor power loss
- Analog input module fault
Troubleshooting Steps
- Step 1: Check 4-20mA signal cable
Cable intact - Step 2: Verify sensor power
Sensor powered - Step 3: Test analog input
Input reads correct value
How to Reset
Reset via control panel after signal is restored.
Source: Schneider Electric ATV320 Programming Manual
Category: PLC & VFD