RS 485 port burn out on CPU

[ericsul]

hello,
Anybody knows how to protect port RS 485 on CPU 001 Versamax GEfanuc from electric noise or other RF etc...
The wiring was done as state of the art shielded cable, optical protected converter RS 485-232 from MOXA AS 53 with individual power supply, What do more to prevent this event to happen again?
Thanks for your advices
ERIC

 

[Singapore_Mats]

your comport use optical converter and still got problem? Then noise is not coming through comport. Check powersupply and your inputs.

 

[ericsul]

Hello Mats,
Thanks for your reply, what I 'm need to check more than I already did. The power supply is protected and earthed and all the analogue inputs are with cable shielded connected on one side to the ground ???? Which kind of checking you proposed ?
Best regards
ERIC