Hello there!
Maybe my question will be more clear if i will describe the system's configuration.
There are 20 plc Premium TSX P57 353 that are linked together over modbus plus with TSX MBP 100 MODBUS+PCMCIA CARDS.
When i want to find out what is going on in the program of the 10's plc, i have to open the program of the controller in PL7 pro v4.4 and connect my programming device with PLC's TER or AUX port using TSXPCX1031 cable. Then i press PLC Connect button in PL7 and my programming device is in ON LINE mode. That works fine! But, when i want to connect to another PLC, i have to connect TSXPCX1031 cable to another port as well.

lyrical digression:
when i have two or more QUANTUM PLC linked together over Modbus Plus i can choose the PLC i want to connect to using Concept interface. I have no need to make some extra physical communications.

The question is:
Can my Programming device communicate with Premium PLC over modbus plus if my programming device is equipped with 416NHM30030 card?
Or:
Can my Programming device communicate with Premium PLC over modbus plus if my programming device is connected to TER or AUX port of the PLC and i want to establish communication with another PLC.

Thank you!

Not that I am aware of. Premium used Unitelway or FIPIO for communication from PLC to PLC. The Modbus Plus was there to allow them to talk to other Modicon products. I do no believe you can connect to a Premium for programming over Modbus Plus, or connect serially and then pass out over Modbus Plus to program another. Pretty sure PL7 doesn't support that.

But then I haven't seen a Premium PLC in 8 years.