SLC 5/03 is not communicating.

[nitinkakade 0]

Hi to all I am new to this forum,I am facing some problem in communication of PLC network. I am looking forward for your help My scheme is as follows(attached) I am able to communicate with 7 no. of PLC's but only one is not communicating(one incircled in RED) I am able to communicate Node no-1 and node no.-3 too,which are connected to Node no-2 via looping.(i had cross checked the Node Nos.) For communication(DH 485 Bus) I am using DF1 (i.e. RS 232 converted to DH 485 in Communication configuration on COM Port 1) using Net AIC 1761 and CP3 cable(because My DH485 port is connected to some other network). I had tried all the possible and suggested solutions for this. One thing remain is to change the CPU of PLC(some one suspects might faulty ports) Please help me out to solve this problem. nitin mrplc.doc

[OkiePC 14]

Did it work before? If so, have you any ideas about what changes occurred around the time it quit? Also, what about the processor LED status indicators? Doesn't the Net-AIC have them too? Edited 19 Jan 2006 by OkiePC

[gravitar 3]

This sounds like something that would be best solved with good old-fashioned component swapping and careful observation. In other words, You have several SLCs that are communicating. Save the program from one of them, put the non-communicating SLC in one of the "working" racks and download the working program to it. Observe what happens. If it works, you know it is something else. Do the same thing with the AICs. Do the same thing with one of the cables. Do the same thing with another cable. Etc. etc. etc.

[rajsiyer 7]

hi Thanking you alll for the nice and helpful solutions. I will try all the suggested solutions.but need some clarification,that is, should I replace the Processor of the PLC which is not communicating. and aslo change the PLC node Address. Thnaking you! Nitin R Kakade