Hi Hellmut,

I have already posted a few comments on other post I found but I can repeat the answers here.

1.- ModelPlug works with Firmata v2.2 but 2.3 is recommended since it has bugfixes.

2.- ModelPlug is just a library for SystemModeler and it is not the only way of communicating simulation models with the world outside the simulation. Simulation executables generated with SystemModeler can be controlled with a TCP/IP protocol. You can find the information within the SystemModeler help with the title "Communication with Simulation via TCP". For more specific use cases, it is also possible to link your own C/C++ code (containing a specific communication protocol) to a simulation executable. You can find more information in the SystemModeler help with the title "External Functions". For an example on how to do this you can take a look at the ModelPlug C/C++ code which is included with the library.