On the boat wiring harness, I only saw a serial out cable wire. Looks like serin split and went to other devices. Didn't look like I could hook up my laptop and manage the unit via serial on the boat. I will double check. I could be wrong. I can get Nema 0183 from it (I think). If I am wrong, I apologize to you and everyone reading. I will look at it tomorrow. My install stuff is at lake.