Raymarine C80 and Multiple GPS Inputs?

[DipperToo]

Hi,

I have an installation with a C80 at the heart of things. The current GPS is from a Raystar 125 (Seatalk) feeding a course computer (S2G) and the C80. Also in the system is an EasyAIS Receiver which I am replacing.

I have just purchased a McMurdo AIS Transponder (M10) which also appears to be very similar to the Comar unit. The M10 has a built-in multiplexer which, like the EasyAIS system, will be passing the fast heading data from my S2G course computer multiplexed onto the AIS data stream, and then into the NMEA port on the C80 running at 38400.

The M10 also has the capability (as default) to pass its own GPS receiver position data also multiplexed with the other data on the NMEA output. Whereas the McMurdo manual mentioned nothing, the Camino manual suggests that the GPS data output can be turned off in a configuration setting.

Question is; Will the C80 be capable of taking GPS position data from both the Seatalk input as well as GPS data provided by the McMurdo unit? Will the C80 prioritise the Seatalk inout so providing redundancy? Or should I just disable the GPS data being sent from the M10 AIS transponder?

Thanks

 

[prv]

I *think* the C-series displays look at Seatalk first, and only fall back to taking position from NMEA if it's not on Seatalk. But I'm not certain. Why not just try it?

Pete

 

[DipperToo]

I *think* the C-series displays look at Seatalk first, and only fall back to taking position from NMEA if it's not on Seatalk. But I'm not certain. Why not just try it?

Pete

Just trying it was the original plan,but I read 'somewhere' a couple of years ago from someone who thought that the C80 sometimes tried switching between the two with strange results unless the two positions were 'exactly' the same. I cannot locate that discussion anywhere.

The Raymarine site only has a reference to their PC App where they say Seatalk takes priority over NMEA.

It would be great to know for sure that with the latest firmware (5.16 IFIRC) that the system does indeed work correctly and ignore the position data from the NMEA unless it disappears from the Seatalk Bus. I would hope that there is a delay before it switches in case of a short interruption by the 125 receiver (or if the NMEA signal appears first on initial power up)

 

[pvb]

You could always simply disable the Raystar 125.

 

[DipperToo]

You could always simply disable the Raystar 125.

Indeed I can. However, of more interest is as to whether the C80 priorities Seatalk over NMEA. That achieves the basis for a redundant GPS. I will investigate further as to whether I can disable the McMurdo M10 outputting position data in case there may be a conflict.

I have found since the original post some unsubstantiated comment that if Raymarine equipment detects a Raystar GPS on the Seatalk bus, then all NMEA position data is ignored. If this is true, then I can achieve a backup GPS data source that will be accepted via NMEA should the Raystar 125 fail.

I will also persevere in trying to get a response from Raymarine.

 

[Gypsy]

I used to have an RC530 and now have an E120W. Both these take GPS from SeaTalk as a priority over NMEA. My current E120W uses SeaTalk from an ST125 (ST) and I have a separate NMEA GPS feeding both my DSC-VHF and NMEA-3 input to the E120W. This gives me exactly the redundancy you are hoping to get for your setup.

On the E120W it shows the source of the GPS signal when you use the GPS-Setup screen. If NMEA is present and not ST then it shows the NMEA data/graphs, when Seatalk is added it displays the SeaTalk data/graphs.

I think you can be confident the C80 will respond the same way.

 

[DipperToo]

Thanks Ray - I will be installing the McMurdo M10 Transponder over the coming weeks and I did not realise that the C80 should allow you to see the GPS data source - no mention in the manual, but maybe the C80 Classic is lacking here. However, from what you have mentioned, it does seem pretty certain that the Seatalk takes precedence and as you say, provides convenient redundancy.

 

[pvb]

I did not realise that the C80 should allow you to see the GPS data source - no mention in the manual, but maybe the C80 Classic is lacking here.

I don't think it does! I had a C120 Classic for about 10 years and I never found that feature. The E120W which Gypsy referred to has a completely different user interface.

 

[Gypsy]

I don't think it does! I had a C120 Classic for about 10 years and I never found that feature. The E120W which Gypsy referred to has a completely different user interface.

The E120W shows the source of the GPS (in parenthesis) in the top banner of the GPS Set-Up page which contains the GPS signal info. Maybe that added info came after the C classics.

In any case, it won't be hard to experiment to see what the Setup page does when disconnecting the ST GPS - spot the difference in signal strength and satellites in use. Specially if you are tied up somewhere and there is little dynamic change for each GPS.

It will probably auto-swap. No reason for RM to change their mode between RC - C - Cwide plotters. Even though the user interface is different it is very clear that the background/base feature set is the same over the years.