Expedition Navigation Software » System Clock Issue

Jaffar · 4/05/2018 11:01 pm

Whilst running Expedition the system clock either slows down or goes backward. This only occurs when the instruments are connected. The instruments are NMEA 2000 which includes 3 GPSs of which 2 are switched off. The 2 that are not used are one in the AIS and the other in a small chart plotter on deck. I assume it is a GPS problem. Every so often the boat location reverts to the cost of West Africa. This has beene happening for a while.

I have changed the CMOS battery but this has not helped. The laptop is a Dell D600.

Lately I have also been getting some strange errors in Expedition. I lost all the instrument calibrations whilst making an adjustment to them last weekend. I should have saved the calibrations and that is my error and this is the first time it has happened. During the same race the course we were using was replaced by another without any input.

Any thoughts.

Nick · 4/05/2018 11:49 pm

There is only one place Exp can set the computer system clock - a button on the tools menu. However, mostly privileges aren't sufficient to do this.

There isn't anything else in Exp that can set the system time.

The west coast of Africa almost sounds like lat=0,lon=0. Which does sound like an issue with the GPS.

How are you getting the instrument data into Exp? As a NMEA 0183 feed, NMEA 2000 from an NGT-1 etc. If NMEA 0183, maybe you have selected to receive WPL or MOB?

us7070 · 4/06/2018 6:47 am

Jaffar - are you sure the chartplotter is not sending position to expedition?

i had a similar issue on a boat where there was a problem with a B&G zeus chartplotter that occasionally sent bad positions (i think mostly the lat was ok.., but the lon was too far east and in africa). the chartplotter got replaced by B&G as they were unable to do anything to fix it...

one check for whether you are getting position from two devices is to zoom in on a track - if it is jittery or uneven when zoomed in.., that can mean two positions are coming in

Last edited by us7070 (4/06/2018 8:24 am)

DuncanR · 4/06/2018 9:50 pm

We also had the "West African problem" i.e. GPS position jumping to Long 0 at relatively frequent intervals. Load your track into Expedition and look for spikes. In our case it appears to that 38400 baud GPS was simply too much sensory input for our fragile instruments; reprogramming the GPS to 4800 baud overcame the problem. Note you can't do that and use the GPS for AIS, which requires 38400 baud.

Jaffar · 4/10/2018 1:16 am

Thank you for the replies. Gives me something to work from.

The feed to Expedition from an NGT-1.

I have turned off the plotter and the problem still exists. I wonder what GPS the AIS is working from. If it is the internal then I did not turn it off correctly. Maybe the AIS will only work while using the internal GPS, I will need to study that further.

Would still love to know where the instrument calibrations went to!!

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4/05/2018 11:01 pm #1

System Clock Issue

4/05/2018 11:49 pm #2

Re: System Clock Issue

4/06/2018 6:47 am #3

Re: System Clock Issue

4/06/2018 9:50 pm #4

Re: System Clock Issue

4/10/2018 1:16 am #5

Re: System Clock Issue

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