Excel DDE question

  daba 01:10 17 Oct 04
Locked

I regularly use Excel to diplay DDE or OPC remote data values, but I can't grasp the techniques needed to be able to change that data by entering the new value in Excel.

Perhaps I'm being a bit thick here, but I thought DDE/OPC was supposed to be a "bi-directional" facility.

Can someone point me in the right direction pls

  cherria 16:23 18 Oct 04

what application are you trying to use Excel to link to using DDE?

  daba 23:42 18 Oct 04

Mostly I'm peeking at PLC (Programmable Logic Controller) values via various DDE/OPC comms drivers, several are used, but the most common is called RSLinx, from Rockwell Software (Allen-Bradley PLCs).

There are an increasing number of times it would be useful to reverse the data-flow direction, i.e. be able to input data into Excel, and get this to 'write' the data to the external application or database. I know for sure RSLinx is not where the problem lie.

My problem is the basic principles involved in getting Excel to accept data input into a cell, firstly without overwriting the formula (the external refernece) in it, and secondly, how to set Excel up to write-out data.

Without being too specific about the external drivers, or the other applications, all I need help with is how to hook-up a bidirectional DDE link in Excel, and providing it's DDE or OPC enabled, it should work with any DDE/OPC driver/application, shouldn't it? I thought thats what DDE was all about - seamless data exchange.

  VoG II 19:47 20 Oct 04

A bit of a specialised question!

Try asking at click here

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