collinsd70 said:
...In brief the older versions of RSLogix5000 wont allow you to incorporate a GSV in your AOI so will need to be read in beforehand.
Not quite...
We all should try to be careful in how we recall our understandings of things or how we have read and interpreted things. I myself had made a poor recollection on something in particular in that thread you have linked and after a helpful prompt from daba I was back on track.
What we were discussing as a limitation in that thread was not that one cannot use a GSV instruction in an AOI in pre v24 projects. What we were discussing was the fact that one cannot use a GSV in an AOI in a pre v24 project with the predefined generic "MODULE" data type as an InOut parameter. This is because this particular and special data type was only added at v24.
For pre v24 projects, one can indeed use a GSV instruction inside an AOI and can, if required, use a specific module-defined data type, of an I/O module that has been added under the I/O Configuration, as an InOut parameter. This is what daba demonstrated in post #19 of that thread.
Also, for further details on implementing a GSV/AOI method to check a module's status, I had provided a couple of Knowledgebase technote article links in post #10.
Note: Get System Value/Set System Value (GSV/SSV) instructions have been around since the dawn of time, or there abouts, but the Add-On Instructions (AOI) feature was "only" added in RSLogix 5000 v16. So only v16 or above projects can use an AOI with a GSV and a specific module-defined data type. And only v24 or above projects can similarly use an AOI with a GSV and alternatively the generic "MODULE" data type, which allows a user to select whichever module-defined data type they require when instantiating the AOI instruction.
If anyone is still not clear on this distinction, between specific module-defined data types and the specific "MODULE" data type, then please let us know and we could try to further demonstrate the difference with illustrations, if time permits.
Regards,
George