logix 5000 stl - calling AOI from AOI

Hi all

I'm trying to call an AddOn Instruction from another AOI. The AOI (wich name is Swap_Bytes) that must be called has only an Input INT parameter and a Output INT Parameter. It swaps the 2 bytes of the input variable and save the result in the Output variable

in the calling AOI I tried many syntaxes, but I'm not able to make it works:


the two parameters that I use calling the AOI are INT variables...

any suggestion?

thank you

Check this note:
Tip:
To nest Add-On Instructions, both the nested instruction and the instruction that calls it must be of the same class type or the calling instruction will not verify. That is, standard Add-On Instructions may call only standard Add-On Instructions and safety Add-On Instructions may call only safety Add-On Instructions.


from this AOI manual:
http://literature.rockwellautomation.com/idc/groups/literature/documents/pm/1756-pm010_-en-p.pdf

You may also need to declare your Input parameter as an InOut type to be able to pass it on to the second AOI.

solved...

the problem was that the variable Swap_Bytes must be declared in the local tag of tha calling AOI, not in the Program Tags


thank you anyway