Omron E5AK PROGRAMMABLE TYPE User Manual page 178

CHAPTER 8 TROUBLESHOOTING
8.1 Initial Checks
8--2
If trouble occurs, first of all check the following:
(1) Power supply
Make sure that the power supply is ON. Also, make sure that the
power supply is within the rated voltage range.
(2) Wiring
Make sure that all cables are properly connected.
(3) Communications conditions
When communicating via the RS-232C, RS-422 or RS-485 inter-
faces, make sure that the baud rate and other communications
condition settings on the host computer and E5AK-T controller are
matching, and are within the permissible ranges.
If there appears to be nothing wrong after checking the E5AK-T con-
troller, and the same phenomenon continues, check the controller in
more detail, for example, on the error display.