Introducing a SeaTalk-ng MFD to an older 150/400 autopilot

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum On The Job,

Please click here to view a FAQ addressing this subject.

Q1. Would I then disconnect the 12v red lead from the SeaTalk B side or both the A and B side of the Autopilot Course Computer?
A1. It is recommended that the SeaTalk bus be disconnected from it's present source of power ... the red terminals of the autopilot course computer. Please click here to view a FAQ addressing this subject.

Q2. GPS. Should the Autopilot Course Computer continue to be running from the original GPS or would the internal A97 GPS handle it and I can get rid of the original external GPS antenna?
A2. Should the a97 MFD be installed in a location affording it an unobstructed view of the skies overhead, then it would be recommended that it be used as the system's source for GPS data (due to its 5Hz updates vs 1Hz updates), necessitating that the currently installed GPS sensor be disconnected from the system. However, should the a97 MFD's installation location not afford it an unobstructed view of the skies overhead, then it may not receive sufficient GPS signal strength to permit it to acquire or maintain an accurate GPS position FIX. In such cases, it may be advisable to utilize the existing GPS sensor or install a GA150 GPS Antenna to permit the MFD to receive 10Hz GPS updates.

Q3. NMEA 0183. It appears to come from the original external GPS. Because the new A97 has an internal GPS do I still need NMEA 0183 inputs? The old NMEA 0183 data appears to be coming from the Autopilot Course Computer which appears to get its data from the external GPS antenna.
A3. It would have only been recommended that the NMEA 0183 output of Gyro equipped 150/400 course computers be interfaced to a display, as the associated 10Hz heading data rate may be used to support radar overlay and MARPA features. Should the autopilot couse computer actually be the 150/400G, then it would be recommended that it's NMEA 0183 port 1 be interfaced the NMEA 0183 of the new display.

Q4. The connection from the old RL70C that is NMEA OUT I believes connects to the Smartcraft through a bus bar. What is your best recommendation that connection?
A4. Should the RL70 remain within the system, then nothing need be changed. However, should the RL70 be replaced with the a97 MFD, then the the NMEA 0183 input leads of the Smart Craft system will need to be interfaced to the NMEA 0183 Port 1 OUT leads to supply the SmartCraft system with GPS data.