Hello,
I totally get where you are coming from and agree it would be very nice to be able to do what you suggest. I will think over this solution more and do some research and let you know what I come up with. Please share any insights you get while setting this solution up.
In regards to Modbus Serial connection [and if you would like to try Modbus Serial again], try following the post below to get access to your serial connections.
Best of luck and thank you,
Kevin