FWD/REV Run Command Input Error

What does EF mean?

This minor fault occurs when both a forward and a reverse run command are simultaneously active for more than 0.5 seconds, indicating a conflict in control signals. The motor will ramp to stop, preventing potential mechanical damage from conflicting commands.

• Incorrect wiring of the forward (e.g., S1) and reverse (e.g., S2) digital input terminals, causing simultaneous activation.
• PLC or control system logic error simultaneously activating both forward and reverse run commands.
• Stuck relay contacts or faulty output module in the control system providing both signals.
• Parameter configuration (e.g., H1-xx) assigning both forward and reverse run commands to the same input or conflicting inputs.
• Mechanical failure of an external selector switch causing both contacts to close simultaneously.

Click steps to track your progress.

1. 1

   1. Identify the digital input terminals configured for Forward Run (e.g., H1-01=01) and Reverse Run (e.g., H1-02=02).

2. 2

   2. Use a multimeter to measure the voltage state of both identified Forward Run and Reverse Run input terminals simultaneously.

3. 3

   3. Review the PLC or control system program logic to ensure only one run command can be active at any given time.

4. 4

   4. Disconnect the physical wiring for one of the run commands (e.g., Reverse Run) and observe if the fault clears when the other is active.

5. 5

   5. Test the external switches or relay contacts providing the run commands for proper operation and isolation.

6. 6

   6. Verify that no two parameters (e.g., H1-01 and H1-02) are configured to trigger conflicting run commands from the same physical input.