Add TwinCat-MQTT interface

[FelixStege]

What is the issue/what feature do you want to develop?

• The already existing MQTT-ADS-interface allows to send MQTT messages over Python
• As an alternative, the TwinCAT 3 IoT Communication MQTT enables the direct MQTT communication from the SPS without further use of external software.

What are the requirements?

• A TC3 IoT Communication MQTT license is needed

How do we want to solve it?

• Add a template to use the TC3 IoT Communication blocks
• Write wrappers around some blocks to simplify usage

[StGoebel]

Did you already add the example function block? @FelixStege

[8OND007]

Is there any fully free (OSCAT based or other) TwinCAT V3.1 MQTT library that does not use paid Beckhoff optional licenses and packages ?

[FelixStege]

The AixOCAT provides one solution utilizing the TwinCAT MQTT library and one solution via Python (no paid licenses needed). I don't know if there are other options in other libraries.