Evolution auto pilot hooked up to c120

[Kenmurgo]

I have an evolution autopilot system that I had been running with a C140W multifunction screen. I replaced the C140W with a C120 and am not sure how to make the evolution autopilot work with it. The autopilot system had been hooked up via STng network to the C140W. The C120 does not have a STng port, it only has a ST2 or NMEA (in/out) ports available. Without being hooked up to the multifunction the autopilot control head will not power on. Is there a converter I can use to hook up the evolution autopilot to the available ports on the C120? Or is it possible to make the autopilot system function without being hooked up to the multifunction screen?