Rslinx & Excel - Writing data to PLC

I was able to read a tag in excel from a Controllogix PLC using =RSLINK|'Topic_name'!'Item'
Am I using DDE or OPC ?

How can I write value back to a PLC tag ?


Thank you.

passwordg said:

I was able to read a tag in excel from a Controllogix PLC using =RSLINK|'Topic_name'!'Item'
Am I using DDE or OPC ?

How can i write value back to a PLC tag ?


Thank you.

Click to expand...

Yes, you can. Search the forum for "DDEPoke".

You will most likely need to add a command button, or some other method to trigger your ddepoke code, as it isn't advisable to write continuously over a DDE/OPC connection.
Anyway, there are several good examples on this topic on the forum, they should get you started.

So I am using DDE not OPC ?

passwordg said:

So I am using DDE not OPC ?

Click to expand...

Yes, DDE for RSLinx to Excel communications.

http://blog.matrikonopc.com/index.php/opc-vs-dde/

For our purposes as PLC programmers using RSLinx, consider DDE/OPC to be one and the same unless you get into something really deep and specialized, Rockwell has utilities to get firewalls configured and setting up these links is easy, I have not had to meddle with the details too much other than install the required bits in the affected machines and configure them carefully.