configuring topic for compact logix in rslinx

Hi,
can anybody help with the proper configuration of a opc topic for compact logix 1769 l35E. I have tried but cannot get data using the OPC client even though the plc is connected in rslinx and can be seen as active in RSWho.I am using ethernet.

first things first ...

look at the Title Bar (usually blue) at the very top of your RSLinx window ... does it say "Lite" anywhere in the title? ... if it DOES, then you can't use DDE or OPC with that "free" version ... specifically, RSLinx Lite can NOT do DDE or OPC (even if the software will "appear" to let you set it up) ...

next thing, how are you trying to "get the data" from RSLinx? ... tell us what software package you're using - and how it's set up ... the more details you give us, the more helpful we can be ...

but ... as a simple answer to your question, usually you just click DDE/OPC on the RSLinx menu - navigate to highlight the PLC of your choice, then click "New" and give the topic an acceptable name - then click "Done" - and that USUALLY does it ...

I am using rslinx classic and compact logix . Hmi is IFIx and OPCpowertool as the opc server. The funny thing is it had worked until i changed IP adresses of both compact logix and the PC. Rslinx still connects and i can use rslogix 5000 but cant get the data through even the rslinx opc client.

personally I'd try deleting the existing topic - and then reworking it from scratch ... if I understand your setup, that SHOULD reset the IP addresses that are involved ...

Thanks. didnt see the earlier attached image. will try those steps

As a note for anyone else that follows this thread in the future, you can also create a topic from the RSWho window. However, to edit or delete (and create) topics, Ron' tips above are the way to do it.

Browse to the controller you wish to communicate with and then right-click and select Configure New DDE/OPC Topic.

OG

Nice work Ron. One Image tells everything. Looks like Brain neurons