Expedition Navigation Software 
- pjl
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Offline - From: Lake St. Clair, MI
- Registered: 11/09/2015
- Posts: 128
Re: Expedition running with a Signet SmartPak
More on this saga. It appears that the Signet only understands NMEA v1.5. Can Exp send v1.5 sentences for the selected "transmit" data when set to the NMEA 0183 mode?
Exp seems to receive and handle some of the Signet system output (AWA, TWD, and some others) when the RS232 interface port and the USB to RS232 adapter are all set correctly. As noted by Nick, check sums cannot be used.
Data is presumably being sent on the RS232 transmit connection, but I have yet to find a way for Signet to receive and use it. Wrong version of NMEA data, v2.0, used by Exp to talk to Signet? RS232 port not putting data on the Signet internal bus because of the Signet architecture?
Comments welcome!
- Nick
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Re: Expedition running with a Signet SmartPak
You can see what Exp is sending in Exp's raw data window.
- pjl
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- From: Lake St. Clair, MI
- Registered: 11/09/2015
- Posts: 128
Re: Expedition running with a Signet SmartPak
Correct. The indented data is the sent data stream. Does that stream identify itself as v1.5 or v2.0 by its characteristics?
TIA, pjl
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Thread Starter- Nick
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Re: Expedition running with a Signet SmartPak
Exp always uses the current NMEA 1038 specification. NMEA is up to about 4.10
- pjl
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- From: Lake St. Clair, MI
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Re: Expedition running with a Signet SmartPak
Just assuming here, but if the Signet SmartPak can only understand v1.5, then this project may have hit the wall.
Here's a known fact. An old Garmin GPS (60 maybe?) hooked into the system provides all relevant GPS data to the system. Changing the GPS to a Garmin 60csx, which transmits v2.0 according to the garmin Support desk, removes all gps data from the Signet displays.
Does't this mean the SmartPak can only read the v1.5 sentences?
TIA, pjl
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Thread Starter- pjl
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- From: Lake St. Clair, MI
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Re: Expedition running with a Signet SmartPak
Nick, This may be a lasssssssssssssst grasp at a straw, but is it possible to add a legacy NMEA 0183 v1.5 mode to the instrument panel?
Thx, pjl
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Thread Starter- Nick
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Re: Expedition running with a Signet SmartPak
What are you trying to send? I don't know anything about v1.5 as it is so old - I see 2.00 dates to January 1992, so it is very old. I had always assumed the data encoding was just a subset. Des the Signet documentation say anything?
I have a recollection the electrical standard was different (232 vs 422).
- pjl
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- From: Lake St. Clair, MI
- Registered: 11/09/2015
- Posts: 128
Re: Expedition running with a Signet SmartPak
My research says that the electrical specs changed from v1.5 to 2.0 and I'm suspicious that the 30~ year old Signet design may make it a deal breaker to get NMEA data into their NMEA port unless it is v1.5.
Lack of schematics and circuit diagrams is another problem with the Signet. Current Signet operation is apparently not equipped or unwilling to provide any legacy information.
I still have a few experiments to conduct as time and opportunity allow, but chances of success are dimming rapidly. Guess the owner will have to consider instrument upgrade, but that will probably never happen.
Thx for your help, pjl
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