The coexistence of modules and third-party devices (eg FM Danfoss, connection IPLC300 - MCIO - M400 - EMU32 electricity meter) is generally not a problem as long as the same communication parameters (speed, parity, number of stop bits) are observed. Due to the fact that I/O modules are very fast, the default communication parameters in the Driver Properties in the IDE are set quite "sharply" - for foreign devices, in case of problems, try to extend one or both time parameters, or. let us know and we'll try: support@domat.cz.
Modules and controllers are connected linearly on the bus, do not forget to terminate the end modules with the switches that are on the module (or from inside the controller, see cat. Sheet).
I would use the galvanic separation in the case of longer lines in a "hazardous" environment (together with foreign devices on the bus, assumptions of higher interference, etc.). (During the six-month deployment, however, we did not encounter a single problem even with galvanically non-separated controllers.)
A four-core cable (JYStY, LAM 2x2x0.8) is not a problem in terms of electromagnetic interference; however, be careful with room controllers with an output to the valve - the consumption of its thermal drive must be taken into account when dimensioning the wires.
The prices of the drivers are in the current price list, please write about them at products@domat.cz. They are in the Process Station section (along with the individual room controllers), which can be slightly confusing.
In principle, it does not matter where the master is physically located on the bus. It is only necessary to terminate the resistors of the bus correctly, or voltage "balance" - but this is taken care of by the internal circuits of modules and controllers together with BUS END switches.
Power supply of controllers: in the catalog sheets there is actually 24 V AC, due to the fact that the digital outputs of the controllers (if fitted) contain triacs, switching at this AC voltage.
For UI010, UI011 (no inputs or outputs) it is not a problem to use DC power supply, you just need to select polarity plus on terminal 7, minus on terminal 6. The controllers work from about 12 V DC, max. Supply voltage is 35 V DC.