KW950E interface negative 35V step Gyro heading to 38400bps $HEHDT

This is a procedure to interface 4 wire negative step at ref. 35V to 38400bps nmea output. I had tested working on a tanker recently with MK37 Gyro compass.
I had study this connection and document down the procedure.

1. Connect step input to SK2, R+  = Ref, S1 = S1-, S2 = S2-, S3 = S3-
2. Link S1+, S2+, S3+ and R+ together
2. Set SW1 to 0000 1010 for 38400bps $HEHDT
3. Connect nmea output to SK3 data output A and B