Stowe Displays and 'normal' NMEA0183

[lpdsn]

Has anyone tried feeding 'normal' NMEA0183 sentences into old Stowe Dataline displays?

I understand that Stowe had a few extra parameters in their NMEA0183 sentences. I also realise they sell a box to do the conversion, but if I'm going to throw money at it I may as well buy new displays, so I'm not really interested in that.

The data will be coming off an NMEA2000 bus through an Actisense convertor (that's primarily there to translate data the other way but has the 2000->0183 translation available).

 

[lpdsn]

Really, has no one tried feeding NMEA0183 from another source into Stow dataline displays?

Looks like I'm going to be bleeding edge then.

 

[savageseadog]

Got Stowe Dataline instruments but don't know the answer. Have you got the manuals?

 

[lpdsn]

Got Stowe Dataline instruments but don't know the answer. Have you got the manuals?

I have, but they don't even begin to provide that level of detail.

I found out from the web that Stowe tended to have extended NMEA0183 sentences, but don't have the information on the extra parameters. If they simply tagged them on the end then their instruments may understand normal sentences, but if not then probably not.

I'm minded to keep the Stowe displays as it would require a bit of research to find alternatives with a similar low profile to replace them, but there's no financial justification to buy a conversion box or actually pay to have 20 year old displays refurbished.

 

[pvb]

Really, has no one tried feeding NMEA0183 from another source into Stow dataline displays?

Looks like I'm going to be bleeding edge then.

Could be bleeding edge! If you have the displays, presumably you have a Databox - this will accept NMEA for GPS data, so might accept other NMEA sentences and send them out on the Dataline. Maybe try feeding the sentences in and seeing what happens.

 

[lpdsn]

presumably you have a Databox - this will accept NMEA for GPS data, so might accept other NMEA sentences and send them out on the Dataline.

Do you mean the R.Nav connection?

 

[rogerthebodger]

My instrument setup is all SIMRAD IS11 driven from a SIMRAD databox X. I have set up connections from the instrument input to my PC running NavMonPC feeding OpenCPN. The instrument displays in NavMonPC do display the same readings as the IS 11 instruments. I know this is not quite what you are asking. I do have a manual showing the all the NMEA message formats but that is in my boat and I will not be there until the start of October.

I do have a plan to connect an IS 11 speed instrument to a RS232 GPS mouse using a PIC to convert the GPS speed message to the format used by IS 11 and as for as I know that is only changing the 3 letter message code as the rest of the message is the same.

My databox is also connected to a SIMRAD auto pilot and SIMRAD radar and all display all messages if that helps.

I will have a look in my manual when I next visit my boat a compare with standard messages and let you know.

 

[pvb]

Do you mean the R.Nav connection?

Yes, that should take NMEA in.

 

[rogerthebodger]

OK found a copy of my manual and this is it on the web

http://www.stowemarine.com/archive/Dataline-X DATABOX.pdf

This may help in your quest.

 

[lpdsn]

OK found a copy of my manual and this is it on the web

http://www.stowemarine.com/archive/Dataline-X DATABOX.pdf

This may help in your quest.

Brilliant, thanks. Much appreciated. That looks ideal.

It looks like I can take speed, depth and wind information from the NMEA 2000 bus through the Actisense convertor and feed it into the R.Nav input as NMEA0183 which will put it on the Dataline bus for the displays.

I think I even have the wires in place as I suspected the PO had a chart plotter connected which he ripped out prior to selling the boat. There are certainly wires connected to the R.Nav input that are hanging loose behind the chart table, so it might be a lot simpler than I expected (although I shouldn't let myself get too comfortable as it is boat instrumentation).

 

[lpdsn]

Bit of an update in case it is useful for anyone thinking of doing something similar.

I fitted a ShipModul multiplexer into the dataline and can now filter NMEA sentences passing between the Dataline box and the Stowe displays. It worked treating the white wire as NMEA+ and the green as NMEA common. The green and the other three (black and red for power and brown for 'data out') are wired straight through.

The lights still work (where you light up one display and the others follow suit). I don't know whether this functionality uses the Dataline box, so to play on the safe side I've allowed all $PSTOx sentences to pass through.

The only non-standard sentence I have to deal with is DBK, which is OK as the only Stowe transducer I still have working is depth. This sentence is passed through unchanged. I intend to keep this transducer when I fit the NMEA2000 transducers, so I'll have two echo sounders working on different frequencies.

I use the multiplexer to filter out wind and speed sentences from the Stowe transducers (these transducers currently don't work, but the sentences are sent with zero values. Maybe Dataline will stop sending them when I remove the wiring from the transducers).

For the next stage I will use the multiplexer to feed in data from the NMEA2000/Seatalk ng bus. Then I'll see if the resultant NMEA0183 sentences (VWR, VLW, MTW, VHW) work on the Stowe displays.

I did try feeding NMEA0183 data into the Dataline box via R.Nav to get the data on the Dataline bus. It may well work on later versions as described by RogerShaw above, but it didn't on my vintage Dataline.