CJ1W- CPU13 network card going bad often

[Big Country 3]

I am new to Omron PLC's but already with the new weld cells that arrived 3 weeks ago we have had a network card go bad. The system consists of a main plc that talks to two other slave plc's. We were warned that these things were notorious for cards going bad especially the power supplies and network card's. Has anyone seen this occurence before or do you have any suggestions for me? Thank's in advance.

[Guest anonymous]

Hello Big Country, Who warned you??? (Bet it was that Allen Bradley guy ). We've had all types of PSUs and Comms cards running here (some even prototypes!) for over 9 years without any problems - talking of which, exactly what are the problems that you are experiencing? What network type is being used? Are all the PLCs CJ1H CPU13? Any further info is welcome.

[Big Country 3]

Yes they are all CJ1M CPU 13

[PdL 71]

It seems to me you have a problem with isolating the controls from the weld system. How is everything grounded ?

[BobB 58]

I have been using Omron PLCs since 1990. The only probelms I have ever had is occassional failure of old 24VDC power supplies, 1 brand new SRM21 - new one fixed the problem and Omron replaced the old one - and an occassional serial port caused by big footed electricians kicking my cable ou when communicating. I have NEVER had a processor failure. Most systems I use battery power through a 24VDC/24VDC switchmode and NEVER ground the switchmode output negative. It would defeat the purpose of haveing isolation in the switchmode otherwise. Agreed. Have you contacted the machine manufacturers about this? Bet they will blame the gear and not the implementation. Another reason to use a switchmode I guess for isolation of course, although I do not play with welders - mainly diesel generators and they have some pretty severe harmonics depending on the pitch of the alternator.