HenryCHB

I've run into the same problem. 

Ideally I would love to have a single FB that I can send a variable array joblist, where the array is of a struct / UDT that has all the information required for the connections and it handles all the MB_CLIENT Control.

As I need an optimsed block for the variable array I cant define an ANY within the Temp or Stat areas. I've found a few workarounds but I am not a fan of any of them:

• Creating an unoptimised function block wrapper for the MB_CLIENT block within which I construct the ANY data type.
• Defining an In/Out as type Any which is only written to and used within the FB. 

Is there a mistake with my understanding? Is there a common solution for this problem?

Making a general purpose building  block is asking for trouble. The closest solution may be to use a two step process. Have the source be pulled apart into a buffer. Then send the buffer out.

The buffer can be declared in the TEMP area of the FC/FB. It is as an array of bytes. Make the size more than is needed. Use the SERIALIZE to push the data into the buffer. One positive is that you will have an indication also on how many bytes contain data.

As I type this I realise there is going to be a problem for getting the source through the FC/FB as a variant. Perhaps then it is best to have a buffer in a DB. First serialize the source to the buffer then execute the communications.