While I have never actually tried kenwood,
The following would be true for all remote base.
You will need a node (private or public).
A form of control, and for kenwood it is a serial connection that must be addressed in your rpt.conf for/in that nodes stanza.
The actual serial interface from computer to radio.
( Pi may be a problem? Should not be as (ie) ttyusb0 /1 /2)
here is some info on the internal command structure…
https://wiki.allstarlink.org/wiki/Rpt.conf#Remote_Base_Commands
For icom, the only radio I know that was set for internal control was the 706mkii and the problem with that is that it was written specifically for it and while most of the commands are the same as other icoms, they will not work because the software is expecting certain length of data returned from specific calls and not all radio’s will be giving it creating buffer underruns and confusing data and causing lock-ups.
I have been writing a external control program for the Icom’s that is very generic and can be limited based on radio. Some radios that do not have function we use a command for are just ignored, but no buffer/lock-up issues.
It works from the dialplan and functions the same on a Pi and should work with virtually all icoms.
Will expand this to kenwood in the future next.
see this thread and contact me off list/PM if interested. I am not doing anything active with this till the weather turns white where I am. But there is a functional beta.