Profibus connection fails to TP170A and TP170B panels

Hello

 I have a profibus network with 12 nodes on. 6 PLC´s and 6 TP panels (2 of them are TP170A and 4 is TP170B)

 The network settings are Standard profile with buad rate on 187,5 kb/sec., and master/slave connection between the PLC´s. The network is segmented with 3 Siemens RS485 repeaters standard version, not with diagnostic. Total Cabler length 1000m.

 My problem/question is: We have experienced several times that the TP panels do not get in to connection in the network, if a part of the network has been “down”. That can be if the Master PLC is turned off, or if the repeaters has been turned off. To solve the problem, can be to power up the panels again, or to disconnect or connect the profibus plug on the panel. Then the panel does get into connection again, and the system is working again.

 1) Is there any solution to this problem?

 My own solution is: You could connect each PLC with its TP panel on MPI network instead, and then only have the PLC´s on Profibus! That gives me then some limitations in download opportunities. You can then not download to each screen via Profibus, connected to TS-Adaptor, am I right? We have a TS-adaptor placed at the Master PLC where we with the current setup can download to all 12 nodes (6 plc and 6 TP panels). This is why I will not make my own solution, 12 nodes on Profibus network should work, so please give me another tip, I will not be glad to have this answer as the only solution.

 By the way it can be TP170A or TP170B panels that fails, there is no difference in that.

 2) Second Question: Can you make a bus fail lamp on the touch screen with out a lot of work? That would make it easier for the customer to see when the problem 1) has occurred. Answer to this question is only interesting if the is no solution to question 1), and we have to live with that.

 Please help me, this someone must have experienced before.

Brg.

MBN