User`s manual

FX communication

Diagnostics 12

12-5

12.4.3 Diagnostics

1 ) Check the status of the RD(RXD) LED and the SD(TXD) LED provided on each

communication unit.

• If both of them are lighted and extinguished, nothing is wrong.

• If the RD(RXD) LED is lighted/extinguished but the SD(TXD) LED is not lighted/

extinguished (not lighted at all), check the setting of the station No. and the transmission

rate (baud rate).

• If the RD(RXD) LED is not lighted/extinguished, check the wiring and confirm the

connection with the programmable controller.

2 ) Make sure that the communication procedure is performed correctly. If it is not performed

correctly, correct the setting in the computer.

3 ) Check the NAK error code and programmable controller error code.

Please see the following section 12.4.1 and section 12.4.2.