Hi again,
in my opinion the CAT can work
Example (I know it can be easier done)
setup with PC-client
on LOCAL PC you run ARCP-480, CAT is setup to the first virtual port = com0
on LOCAL PC you run PstRotatorAz, rotator is setup to the second virtual port = com1
on LOCAL PC you run Expert-1K software and is setup to the third virtual port = com2
on REMOTE Side RRC-1258 MKII ttl port goes to the ts480 ttl port
on REMOTE Side RRC-1258 MKII com1 goes to the rotator control
on REMOTE Side RRC-1258 MKII com2 goes to the expert-1K comport
on REMOTE Side you connect pin3(tx) and pin 5(Gnd) of the TS-480 comport (on front) to pin1 (RS232-RX) and gnd to pin4(gnd) of the expert DB15 (also connect alc and ptt from 8P minidin to this connector, The expert will auto follow the radio.
Guy ON4AOI