EWO, Active X or something else

[mhargreaves]

I am wanting to send messages to read/write data from a user interface to a separate service which we have developed. Is the best way of doing this to use an EWO, an ActiveX object or some other method?

[fmulder]

Well first of all. The ActiveX is the last thing I'd consider. ActiveX's have often caused me headaches.
The EWO is also not the best choice because a) it is complexer and b) wont work from a control manager

There are various choices that are more simple to build:

1) a C++ control DLL (when it is a 'sometimes' command )
2) A C++ manager or driver (when it is continous)
3) A C# manager

There's a an X-File that describes how to make a control DLL

Hope this helps

share the fun
Frenk Mulder

[mhargreaves]

We have developed a C# manager anyway, but are not sure how to send a request for data from a UI button (say) to our manager - would this have to go via a datapoint or can you call functions directly from the UI and return data directly to a UI?

[Gertjan van Schijndel]

You could also use existing communication functions like 'udpOpen/udpRead/udpWrite/udpClose' and/or the tcp variants to communicate with an external program.

Normally all communication with other managers is done with datapoints.

[agruber]

If your separate service provides a webservice, use netGet/netPost to get/set data. That's what I would do, as it is probably the most convenient way, no need for separate compiled programs/libs, just plain CTRL.

BR,
Andreas