Hello to everyone

We have a profibus network with 41 nodes (include CPU 317-2, CPU 313C-2DP, SIMOCODE and . . .). The master PLC is CPU 417-4 with CP443-5 Ext and for programming we use PCS7 V6.2 . There is one Repeater on this network and on each segment of repeater we have less than of 30 nodes. Now I want to add a CPU 314C-2DP V2.6 to this network as slave PLC. After I've added CPU314C-2DP, the master PLC have Internal Fult and some devices on network, their connection been instantly interrupted and on OS (monitoring system) are blinking.

In the diagnostic buffer has "I/O access error when updating the process image input table leaving state" message. I've attached the diagnostic buffer image.

Please help me to fix this problem.

Best Regards

Hello,

you can confirm that new cfg is ok, downloaded without any problem? How you did cfg of that new added S7-300 CPU? Maybe you can check available I/O for exchange, if you have not reach max available. Sry, your info is not enough to see something. Your network is complex with many slaves and different I/O slots probably. Pls save your diagnostic buffer as complete txt file from CPU diagnostic screen and attach it here. You can also make screenshots (HW cfg, ...) with PrtScr and use IrfanView to save screenshots as JPG, then zip them and attach zip file. Hope then we can find something.

Dear Duris

Thanks for your answer.

Actually I'm sure that HW cfg. is OK and consistency check is OK.  But when I've downloaded HW cfg to PLC,  node No. 58 (CPU 317-2) been instantly intrrupted (every 6 second) . After that I've connected the profibus connector to DP port on CPU314C-2DP, I could send and receive data from CPU314C-2DP without any error. All of the addresses in the CPUs are OK. I didn't change any parameters on CPU 317-2.

At below shown diagnostic buffer errors:

Hello,

maybe what I can recommend is put inside Slave n.58 (317-2???) OB86 from Library, simply download that OB86 inside it. This can be temp solution as generally due that Rack Failure. Due this Failure you can check maybe some Power comsuption of CPUs, maybe new added use also some Power supply as also 317-2 CPU, simply this idea quick comes to my head. In other case nothing against to other checks on this 2 stations (new added and 317-2), back black BUS connectors, grounding, other CPU diagnostic buffer events what can point to some other problems. Be carefully with DP cables correct wiring and shielding to inetrnal plate of connectors, other good checks... I think you will find something. Good luck to investigation and pls give us info.

Dear Duris

I've checked the CPU 317-2DP program online, it had OB86.

I don't undrestand why after download  HW Cfg. on the master PLC (417-4), the CPU 317-2DP be instantly interrupt and the master PLC has INT fault when not connected yet the profibus connector to CPU 314C-2DP.

But when I connect the profibus connector to CPU 314C-2DP I can send and receive data without any problem and CPU317-2DP still faulty.

And when I delete the CPU 314C-2DP station and download HW Cfg. to the master PLC again, it be OK.

I've checked all of the addresses on 2 CPUs, everything were OK.

I've attached system layout drawing for this network. I just add a CPU314C-2DP on it.

Best Regards

Hello,

hmmmm pls post picture of your HW cf if it can contain all on one screen or in case of more screenshots - svae parts of HW cfg and then zip them. Really hard to recommend something but I'll be make little test with disconnect some part of network (if you can do this test) where are big size of I/O transmitted. Connect now both of your CPUs - 317 and 314. What situation shows now? Check also on your 41x CPU presence of OB86 for sure but that test with disconnect some part can be interesting. It can maybe point problem with overused max number of I/O (maybe). Sry but my idea can be only this now...

Dear Duris_I

After some month, now we have overhaul in factory. I have checked all of things I thought. Now, I have understood just the master PLC and this PLC are active in the profibus network. I thinking this is the problem because the master PLC must be active and the slaves passive.

What are you thinking?

Hello to everyone

I found the problem. I've changed configuration of DP slave on operating mode tab from active (default) to passive (Deselect the option “The module is a passive node on PROFIBUS” ).

Best Regards

Seyyed Mahdi Esmaeili

Hello to everyone

I found the problem. I've changed configuration of DP slave on operating mode tab from active (default) to passive (Deselect the option “The module is a passive node on PROFIBUS” ).

Best Regards

Hello, when I try to do that,  I get this message.