Raymarine RL70C with A75 problem

[Capt.Don]

I'm troubleshooting a very strange problem with my Raymarine RL70C and A75 chartplotters, networked together. It appears the A75 is sending the Goto Waypoint/Cursor even after the Goto is cancelled on the RL70C. The symptoms are: (1) select Goto waypoint/cursor, (2) select Cancel Goto. On the RL70C the Goto is cancelled and then immediately resumes. There's no way to cancel the Goto - it always reactivates the previous Goto.

The RL70C is our main chartplotter w/radar and chart chips for our cruising area. Earlier this year I installed an new EV-400 autopilot, along with a SeaTalk NG backbone. The A75 is mounted below. I was hoping it would display chartplotter and instrument display. The A75, EV400, EV1, i70,... make the SeaTalk NG network (works great). I also have a SeaTalk to SeaTalk NG bridge to connect the legacy SeaTalk instruments and the RL70C. GPS feeds SeaTalk NG which is properly displayed on both the A75 (SeaTalk NG), i70 (SeaTalk NG) and RL70C (SeaTalk).

If I disconnect the A75, this problem goes away. Reconnecting the A75, the problem resumes. I've changed the A75 'Data Sources', selecting the dedicated instruments. There's no way to turn-off the A75's as master controller for the SeaTalk NG network.

This appears to be a timing issue between the RL70C and the A75. The RL70C sends the Stop Goto. This is translated from SeaTalk to SeaTalk NG. It appears the A75 gets the Stop Goto; meanwhile, the A75 resends the Goto, which is sent back to SeaTalk. The RL70C sees the Goto and resumes. The A75 never resends the Stop Goto -or- this is a bug in their software.

Are there any advanced or dealer only settings that would put the A75 into a read-only mode? I don't want it to control the autopilot, waypoints, gotos, etc. just display boat's position on the chart. Ideally, if possible, I'd like to use the A75 to display the boat's data (GPS, wind, speed,....).

Any other suggestions for making the A75 work in my environment? Otherwise, I'll need to disconnect the A75's STNG cable and use its internal GPS for chart display.

Thanks,
Don