A1Sj comms module

Please Help !

The aisj24c comms module has gone u/s on one of our PLC networks.Upon contacting our installation engineer he informed us that it is just a matter of turning the unit off and changing the module (ensuring that all the dip switches and mode selector dials are the same).However we have now tried two new comms modules without sucsess.The hard wire terminations and continuity have been checked. Any ideas .

Assuming you are using a A1SJ71C24-R4 or A1SJ71UC24-R4 then the only thing I can sugest is checking the station number setting swithes marked x10 and x1 are in the right position and that no other module in the system is using the same settings. You can check the operation of the unit by using the mode selector switch in position "F". You will need to read the manual for this !

A1S Comms Card

Is it a network card A1SJ71AT21B, or Comms Card A1SJ71UC24-R2 ?

If its the network card, how did you know the original was defective ?
(Does it show any error led's)

What are the symptoms of the problem.
I agree with the advice you were given, the cards can be exchanged and should function without problem if the configuration of the switches and wiring are set-up as per the original.

Could it be the PLC, where the suspect card is slotted is actually causing the symptom.
(What is the network being used for)

Gene it is a Comms Card A1SJ71UC24-R2. The reason we know it is defective is that when it is wired in it is locking up the P.C based control station. With the new unit plugged in it is not.

Sandbag we have checked all what you suggested with no joy.

Comms Error

Hello Orwell,
Sorry but I still can't get my head around the fault you have.
The card we are talking about is the RS232 comms module, Mode selector rotary switch, Dip switches and RS232 (9 Way).

Which LED's are illuminated, or illuminating on the Card ?

Is the PLC CPU error light off, and which CPU are you running ?

What is the 232 Port interfacing with physically ?

Perhaps the original card took out some logic at the other end.

Regards,
Gene.

run modw error

dear,

anyone know why the plc can not goes to run mode?
how to switch to run mode, is either turn key or wiring input, pls advise due to i m not in the factory.

very appreciating, if u could help.

thanks.

Herman

Orwell

Have you tried a loopback test on this card. The test details are given in the manual and this would eliminate the possibility that the problem is outside the PLC.