GPS/NMEA not being read by Cmap on Laptop

[demonboy]

I've been given a second laptop to hook up to my Garmin GPS 17 in order to plot my position using CMapECS software. The laptop runs Windows 2000.

The problem is I can't seem to get the laptop to receive the GPS signal and wondered if anyone can help.

I've configured the COM port correctly (4800 baud etc etc) and have successfully downloaded log data via a serial connection to my Navtex. When I then swap that connection from the Navtex to the GPS unit, the GPS is not recognised. What I'm saying is that the wiring on the serial DB9 female connector is correct, so it can't be that (ground=Pin5, data out = pin3 and data in=pin2).

I don't imagine I'd need a driver for the GPS 17 unit either, as it makes no mention of this in the installation instructions.

If my wiring is correct then the only thing I can think is that there is something on the laptop not configured correctly. Bear in mind I've configured the COM port via the Device Manager as per the CMap instructions.

Does this situation sound familiar to anyone? If so, do you have any suggestions for trouble shooting?

Thanks for your help in advance!

 

[Talbot]

have you entered the Cmap ECS config set-up and confirmed that the port that the GPS data is using, is also the port that c-map is expecting - this is the normal problem

BTW getting hold of Maxsea version 10.3 is the best way of using C-map charts, the ECS is such a basic plotter that it is a real pain, as is the need to change the colour set up. Maxsea is a great plotter software and also overcomes these problems.

 

[chasroberts]

I had a problem with incompatability of GPS NMEA feed and system requirements. One wanted NMEA0182 and would not work with NMEA 0183. Long shot but might be worth a look at what you've got/need?
Good luck.

 

[AlistairC]

You wont need a driver for an NMEA source on a serial port, did you check that the garmin is set to NMEA rather than Garmin's proprietary protocol, that would do it.

 

[alan]

You could try "HyperTerminal" on the laptop to make sure that you are receiving vaild NMEA sentences from the Garmin (Start, Programs, Accessories, Communications, HyperTerminal).

If that is O.K. then maybe you need to set the correct comm port on the C-Map ECS; I'm not familiar with ECS but on other applications you need to set the comm port that you are using.

Alan.

 

[wotayottie]

In no particluar order:

1/ If you are using the lappy serial port - OK. If you are using a serial to usb converter, go to device manager and check that the converter software (usually from Prolific) is enabled and running when the GPS is connected.

2/ drill down in device manager and check that the port nominated is the same one that the config sys file in C map is expecting and at the same speed

3/ check that the gps setup is configured to enable the interface to work and in NMEA at that.

4/ I assume that you are getting all the charts up. The usual cause of problems in that area is the wrong file structure on your lappy. Read the manual.

5/ When you installed C map did you read the manual and make sure the files they specify were changed from read only ?

 

[demonboy]

Hi all,

- I've checked the NMEA interface from the GPS unit, which is 0183 v2.0. I assume is the correct version for CMap. Do I configure this in CMap anywhere?
- I have checked the corresponding COM ports so that they tally between Drive Devices and the expected port for Cmpa-ESC.
- I used Hyperterminal to prove that I could receive LOG data from the Navtex, though not live GPS data. That worked when I wired the three DB9 wires to the Navtex junction box. I don't understand why I can't receive NMEA data though.

One thing that is strange is that the GPS Port 1 Data In wire (blue) was not connected to anything. The GPS cable goes into a B&G junction box and feeds the B&G plotter, VHF and Navtex, which all receive live GPS data.

If I use HyperTerminal will it show live, changing GPS data? As I said above all I receive is recorded log data from the Navtex.

 

[wotayottie]

the data connections will be the same for all data - I cannot comment on hyperterminal since I use one of the free gps progs to check.

one thing I forgot to mention was to ensure in cmap setup that the NMEA sentence it was looking for was one being given out by your gps

 

[fireball]

hyperterminal set with the right settings on the right comm port will show you the raw text data being received on the comm port - would be a good place to start.... that way you know it is not your wiring....

 

[demonboy]

According to the instruction manual for the Garmin 17 it says the following:

[ QUOTE ]
Serial Port 1: Selectable between NMEA and Garmin. NMEA 0183 v2.0 (ASCII), GPALM, GPGGA, GPGLL, GPGSA, GPGSV, GPRMC, GPVTG, PGRME, PGRMF, PGRMT and PGRMV output.

Serial Port 2: RTCM input only. RTCM SC-104 differencial input messages types 1, 2, 3, 7 and 9.

[/ QUOTE ]

In Cmap you only have a choice of two different NMEA 'tokens': RMC or GLL/VTG. Perhaps this is where I am getting confused? I'm not sure a token is the same as sentence. If it isn't, where do I set my NMEA sentences in CMap or should I be looking to change something else instead?

 

[demonboy]

Sorry Alastair....only just read your answer. As it states in the manual 'Serial Port 1 selectable between NMEA and GARMIN'. Any idea how I change it from Garmin to NMEA? How do I know what it is broadcasting? If it's feeding my VHF, Navtex and plotter already then it must be NMEA?

 

[AlistairC]

Hi,
if you're getting the position on your VHF then it must be NMEA at 4800bps, so its not running Garmin's thing.
I agree with the others, run hyperterminal, check you work with the navtex, then if that doesnt work check the cable between the serial port and the nmea output. Check you havent got data in/out round the wrong way on the pins (I think its the other way round on the DB9 compared with DB25), thats my favourite cock up.

 

[Spyro]

I use Cmap ecs. Don't know if this helps but the settings on mine when you go into CMAPECS config.exe are, under the tab NMEA config I have talkers as GPS, comport is "comport1", and NME tokens is "RMC".
Output from My GPS is NMEA 0183 1.5.
Doesn't mean a lot to me but it works.

 

[Guest]

In your CM93 folder you will find the file : config.exe .. click on this and you will have a large dialogue box come up with a lof of tabs along the top.
Select <NMEA configuration> ..... you wil have columns ... Talkers ..... COM Port .... NMEA tokens

My settings are : Talkers = GPS .... COM Port = COM3 ..... NMEA tokens = RMC


MAKE SURE you click OK after changing any detail and this applies to each page you change something on ...

Second ... on Garmin - you must have a menu possibility to select Garmin or NMEA protocol ... you must have it at NMEA ...

If you are unsure of which port your Garmin is talking to .... go to Device Manager and have all devices showing ... click on Com Port listing and have that expanded ... now plug in GPS to serial port - it should now indicate something ? Unplug and see if anything changes ... the change will be the port you need. (this is especially successful when you have a USB conversion from serial lead ... )

As another says Maxsea is much better to display CM93 ... as it uses higher display colours setting instead of 256 as in CMapECS ...

 

[demonboy]

Ta-da! Done it!

Thanks for your help, all of the above. I followed various advice by using HyperTerminal first in order to confirm I was receiving NMEA and it turns out, as Alastair suggested, that one wire was the wrong way round! Just a little confusion over the definition of IN versus OUT. Idiot.

One thing that I would still like to question - heading and log are still red (not green). I'm stationary at the moment so I understand the log is not registering but shouldn't my heading be displayed?

 

[Mrnotming]

Hi Demonboy,

My boat and another friend's boat both exhibit a fault that when plugged into shore power, the Laptop will not display the GPS input. So much fruitless headscratching is solved by unplugging same shorepower and substituting either battery adaptor or the cheapie inverter. All then bursts into life and the little swinging icon of ship appears.This does not happen at home for some reason, in my case anyway.The phenomenon is evident in Ireland and also France Italy etc.My laptop is an Armada 7400 by Compaq.The other boat has a different model , Dell,I believe.
Nmea seems to exists in groups of voltages or bands of voltages, and these seem to be easily upset by AC shorepower.May not be the answer in your case, but could lighten up somebody else's day!

 

[Guest]

Heading can opnly be displayed by GPS comparing positions and calculating displaced position ... so technically no heading will be possible when stationary ... but in practice the heading marker will swing / move around as position varies ....

As to what shows as heading marker etc. - that can be changed in config.exe ...

 

[Jenni]

I recently cleaned up a friends laptop. Asus VERY old. It runs win xp professional. He has been using it FOREVER. I backed up the data for him just in case the laptop stops working. It looks like its fallen many times. Needless to say his cmap was working perfectly BEFORE i backed it up. I haven't changed anything. Now it suddenly says the NMEA port doesnt open. HELP PLEASE. His GPS is on a USB port.

 

[AngusMcDoon]

You will get a better response if you post a new thread describing your problem rather than adding to an 8 year old one. Try it. It's free.

As to your problem, it may be that the port number is now different and you need to go into the computer's device manager to find out what the port number is and adjust the settings in OpenCPN.