If the CNC control 'hangs' on a command to the PLC, and displays the error "Failed PLC Communications..." after pressing the Esc key, you may need to run PORTTEST to determine the cause of the problem.
If you have power and the connections are good, and you unplugged and replugged the cables, the next step is to run PORTTEST.
PORTTEST is a simple app installed on the OmniTurn to test the communication port that the CNC uses to 'talk' to the PLC.
If the port fails, run PORTTEST at the motherboard using the 9 or 25 pin loop-back connectors that shipped with the PLC or loader. Set the CNC power off, disconnect the ribbon cable that is attached to the RS422 converter, put the loop-back connector on the ribbon cable and run PORTTEST again.
Below are illustrations and captions describing the entire process.(These are G4 CNC screens; for G3 screens click here)
The results will be "Test failed" or "COM3 (or COM2) is OK".
If failed, the next step is to repeat the PORTTEST at the input of the RS422 converter to see if that's the culprit.
If OK, the next step is to carefully examine the cable between CNC and mini DIN connector at PLC. This wiring diagram shows pin numbers to ring out.
A special PLC DIN loop-back connector is available if necessary.
G3 CNC: When the control boots up to the File Backup prompt, press Ctrl-C instead of y or n and you will drop to the DOS prompt, which will be C:\OMNITURN_
If waiting, press Esc key. The next step is to repeat the PORTTEST at the input of the RS422 converter to see if that's the culprit.
If OK, the next step is to carefully examine the cable between CNC and mini DIN connector at PLC. This wiring diagram shows pin numbers to ring out.
A special PLC DIN loop-back connector is available if necessary.