Elk M1XSP - can I use for RP?


Active Member
I just bought a used Elk M1XSP. I got it added to the Elk M1, changed the firmware from Uplink back to standard serial expansion. Removed the J5 power jumper.
Made a cable. When I try to connect with RP2 I get "incorrect serial number or incorrect remote programming code". Baud rate is 9600.
Whats the trick to make it work? The cable is only 3 wires. Any other wiring scheme gets me "unable to determine baud rate". Can I use the M1XSP for RP2?
When I move the cable over to the M1G built in serial port it works correctly.
As far as I know/remember, you can only use the onboard serial port for that type of traffic.