MARPA and SHS

[danderer]

I’ve got a legacy installation consisting of two E80 displays, Raymarine GPS and radar, an S2 AP Course Computer, fluxgate compass, and an 8002 AP control head.

The fluxgate is connected to the AP Course Computer, and the AP Course Computer to the 8002 via Seatalk, and then via Seatalk to an E80. The E80s are connected via Seatalk HS.

I bought and installed an external gyro (“Smart Heading System”) to improve the AP function. The only currently connected output from the SHS is a 2-wire connection to the Rate Gyro port on the AP Course Computer. The fluxgate remains connected to the AP Course Computer, not the SHS.

As expected this allows the AP to AutoLearn. AP performance is somewhat improved.

A second benefit I hoped for was improved MARPA performance. Is this single SHS->AP connection adequate to gain that? In rereading the manual I see mention of additionally connecting the SHS to an E80 via NMEA. I have not done that. What is the benefit of that connection--to get improved MARPA performance? Can the connection be to either E80 or must it be the E80 connected to the radar?

If NMEA will improve MARPA, how significant will that be? Both E80 NMEA ports are already used (depth sounder and AIS), so I’d need to invest in a mux to connect the SHS. Will the MARPA improvement justify that expenditure?

Thanks.