Hello, Fine Folks!

Ever since I discovered that there is no horizontal slider control built into Flex, I've been investigating how to make my own ActiveX controls. So far, I have experienced some limited success using (don't laugh) Visual Basic 5, a VB that pre-dates .NET technology. Since I'm developing at the moment only for Flex Runtime on PC, this works without any special Flex SDK.

Now, before one of you refers me to the Open Platform Program, I should tell you that I contacted Klaus-Wilhelm Lotte (referred to here) several weeks ago, and he informed me that the Open Platform Program is no longer available. (If that is so, it would be nice if the literature from it were available somewhere.)

Anyway, on my own, I've figured out how to make events work from the ActiveX control, and the properties that respond to Tag changes at runtime seem to work, too. As a side note, I've even learned how to use VB Script in Flex to write into the ActiveX object properties, whether or not tags are connected to the properties.

ActiveX properties that are supposed to output to a Tag are a different matter entirely. The code mechanism that allows reading from a Tag into the object's properties (boolean and integer types are what I've played with so far with VB's Get and Let statements) appears to be entirely inadequate for the purposes of sending data out to a Tag. In other words, I can only seem to get data from tags but not to them using the ActiveX property interface. It is possible to use the events to trigger a VB Flex Script to do this work, but that seems like an extra step that I should not have to take, and, more importantly, probably suffers from a performance hit.

So I'm asking if someone can show me VB ActiveX sample code that can write to a connected Flex Tag or otherwise provide an explanation of how to do this.

Kind regards,
The Captive Engineer

I still would like some answers (and some literature if any is available), but I have learned a bit more since my original post.

Evidently, a data element inside the ActiveX object must be bound to the connected Tag at the interface. In VB5, this is accomplished through one of the menu tools instead of within the code itself.In this case,whatever programming structure accomplishes the link of ActiveX data to Tag data is added to the VB code once it is compiled into the ActiveX object code. No changes appear in the source code concerning this data binding.

There does appear to be one more problem. It seems I can only successfully bind data to one Tag at a time. I can have several tags connected to the ActiveX object, all of which would pass data into my object, but only one which receives it back out. So far, whenever I've tried more than one, the ActiveX object fails to transact data outward, and I'm liable to get a VB Script error if I attempt to spy on the object in Flexand even fatal exception errors in the HMI runtime itself. I'm not sure if this is a limitation of VB5 or of WinCC Flex's object model. Here again, some documentation regarding this aspect of Flex would be really useful.

Struggling along,
The Captive Engineer

_{Thus spake Hosea, "My people are destroyed for lack of knowledge."}