C-80 problem

Alyssa Jean

New member
Just got back from an overnight in the San Juans. Yesterday I noticed than the speed window on the C-80 was registering about 2-3 MPH less that the speed on the Navman. Both get their input from NMEA. Then today on the way back the speed indication on the C80 went to 0. In looking at the wiring I discovered a wire hanging loose and have no idea where it was connected. It looks as though it came out of a crimp type connector. The wire is one of the wires that comes from the GPS Raystar 125 ant. The brown one. Which in the manual says it should go to RTCM in /+. I have no idea what that means and also can't find any wiring diagrams showing the wiring of the four or five different plugs that plug into the back of the C80.

What also baffles me is that I am still getting GPS SOG in MPH on the Navman.

Anyone have any thoughts or info on this?
 
I don't have my C70 (C80 installation appears the same) yet but I have been downloading PDF's from Raymarine. I don't know which manuals come with the equipment but possibly their PDF manuals "C Series Display Installation Manual" document number 87020-2, April 2004 and the Raystar 125 manual on PDF may help - I am sure the latter is included with the Raystar 125. Regarding your Navman conflict I have no idea - not familiar with the equipment.

cheers - Dave
 
David,

Don't know about the wire problem, but the SOG in mph can be changed to knts by going into the Memu, selecting, setup, units setup, speed units, Knots.
 
David,
You could try calling the raymarine help line. They would probably be able to tell you exactly where that wire should be connected. They have helped me with my C80. \
Good Luck,
Steve
 
Yes that is a connection that is used when you utilize SEATALK.... the C80 can use NEMA or SEATALK.... the beauty of SEATALK is the ability to interface different inputs into one box... I don't think your C80 needs anymore than NEMA direct connections... in fact I don't think they package SEATALK boxes into the packages anymore. In the past the SL70 series Ramarine units used a GPS SEATALK connection.

Joel
SEA3PO
 
The wiring connections appear to be detailed on pages 4 and 5 of the Raystar 125 installation manual. The term RTCM is a standard somewhat like NMEA. Am I stating the obvious or adding to the confusion?

cheers - Dave
 
RTCM (Radio Technical Commission For Maritime Services) is used if you have an external DGPS receiver (Not likely). Most likely your GPS 125 is connect to the C-80 by a SeaTalk connection and the brown wire should be grounded - usually it would be crimped along with the shield wire in the same terminal. If you are using a NMEA connection, the green wire would also be connected to the shield wire. For Sea Talk the green wire goes with the red +12 volt wire. See manual @ http://www.raymarine.com/raymarine/Subm ... 7_3www.pdf

Hank Brooks, Sea Skipper
 
Here in my be your problem...note "RED" instructions:

----------------------------------------------------------------------
NMEA sentences
Output sentences:
GPGGA, GPGSA, GPGSV, GPGLL, GPRMC, GPDTM, GPGNS, GPVTG, PRAYA
Input sentences:
PRAYI, PRAYE, PRAYA
Note: If the Brown (RTCM) and Green (NMEA in/+) wires are not used, they must be
suitably grounded.
 
Thats it, the brown is grounded if not used. Thanks WhalerGoFar and Sea Skipper. I couldnot find the reference wiring diagrams with the notes that brn goes to ground.

Go out and fix it as soon as it gets light. And guess I will have to put her in the water today to see it all is okay.
 
Are you inferring that it rains in the NW? Actually the annual rainfall here in Anacortes is only about 30" a year. And to answer your question, my port wiper doesn't work worth beans. There is no tension from the blade to the window. It keeps coming loose where it is mounted with a set screw to the wiper motor shaft. Maybe need a new upper wiper blade assembly. Or maybe I can increase the spring tension on the blade arm.
 
Okay, the no signal problem is fixed by re-grounding the loose wire. However there still is a differential in what the C80 shows for speed and what the Navman shows. They both get the same signal from the NMEA output from the ant. The Navman shows 3-4 MPH higher than the C80.
Could it be caused by not enough power input now that I am powering two units with the same input. A question for Les on Tues. if I can get him to answer the phone.
 
Ideally the C-80 should be connected to the GPS by SeaTalk which has a much higher bit rate rather than NMEA. The C-80 will convert the SeaTalk data to NMEA which can be connected to the Navman. Also for each NMEA port, it is best if you only have one NMEA talker & listener connected to each other. Both NMEA & Seatalk are digital signals so it is unlikely that a weak signal would result in a different speed reading. Perhaps one instrument is reading in MPH and the other in Knots? Or if you have the Raymarine depth~speed sender, you may be looking at speed over water (SOW) on the C-80 and speed over ground (SOG) on the Navman?

Hank Brooks
Sea Skipper
 
David,

I don't think its serial power issue since NMEA normally will "power" at least two devices. I have three powered by a single output on my Lowrance. I think it is an issue of how each device is interpreting the messages. The question is which device is recording the true speed. It's kind of like having two watches.

I would think a more classic installation would have the Navman taking speed over ground from the C-80 NMEA output and not from the GPS receiver itself if the C-80 has an output.

The GPS125 receiver is outputing in NMEA 2.3 format and the particular sentence the NAVMAN is looking is the GPRMC. There might be an issue with the NAVMAN looking for NMEA 2.2 or earlier output in which case the NAVMAN may not be decoding the RMC sentence correctly.

Only a guess, but it might be a factor.
 
I may be wrong here.... but it seems that in one of the menus on the C70 Raymarine, you could even calibrate the speed. I think it has to be in the sonar mode, then a couple/few button pushes.... I no longer have the system, or the books... But, when my brother Mike's grandson was "adjusting the screens" on one of their outings..... he did manage to re-set the speed calibration some how... :shock: But at the same time... Mike had a brilliant idea.... no child goes forward without a roll of paper towels and windex. That worked great...and I could care less what the speed indicated.....I could SEE !!! :smiled :lol:

I recall post on a different thread about the speed being changed or calibrated in the sonar menu.

Yep, I had to grin with Bill on Halcyon....about the new purchases. Raymarine is real good stuff..... if.... you read a lot and push a lot of buttons. David, I have all the confidence in the world you will have this fixed too in no time at all. I use to keep my Garmin 76S sitting between my two Raymarine C70s on FreeByrd... because I was simply use to the flow of the button pushes.... and nothing like a bit of back up if all DC power goes away. There was a day when all three instuments agreed on the rate of speed....
 
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