Fred, Thanks for the clarification. I realize that the two are completely different and that my choice of words relating the two was misleading. The link I incorrectly referenced was the third part of a more general discussion of SeaTalk and some of the relations between it’s datagrams and NMEA sentences. I should have referenced: http://www.thomasknauf.de/seatalk.htm, other parts of which contain descriptions of how SeaTalk works and the structure of the SeaTalk datagrams. I was trying to answer Josh’s question regarding the version of NMEA0183 relative to the ST60 instruments, and, as you have pointed out, there doesn’t appear to be an answer. I did use the device: http://www.raymarine.com/view/?id=1597 along with the adapter cable A06046 (male) to tap into the NMEA 2k bus. Prior to installing the NMEA 2k equipment, I had used a Ship Modul multiplexer to convert SeaTalk data to NMEA0183 sentences, but this seemed like the cleaner approach since I already had the ST-STNG converter in hand.
Monty Scandia 1991 C&C 34+ Annapolis, MD On Mar 30, 2014, at 11:33 PM, Frederick G Street <f...@postaudio.net> wrote: > Monty — SeaTalk 1 (the original SeaTalk protocol) is NOT a variant on NMEA > 0183 — the sentence structure is completely different! The link you included > about reverse engineering is to allow you to view the sentences on a PC; but > it doesn’t convert into NMEA 0183. The reason there’s no version of 0183 > listed for the ST60 instruments is because they are NOT NMEA 0183 devices; > and unless you have smart transducers that output either NMEA 0183 or NMEA > 2k, you won’t see any digital data from the transducers themselves. > > As you mentioned, you need a SeaTalk to SeaTalkNG/NMEA2k converter to make > this work. BTW, the old SeaTalk is carried on a sixth wire on the SeaTalkNG > bus, which it part of the reason ST NG is not a direct NMEA 2k replacement. > > It sounds like you used one of these: http://www.raymarine.com/view/?id=1597 > along with a Raymarine A06045 Seatalk NG to DeviceNet (NMEA2k) adapter cable > to get from SeaTalk to NMEA 2k. > > Fred Street -- Minneapolis > S/V Oceanis (1979 C&C Landfall 38) -- on the hard in Bayfield, WI :^( > > On Mar 30, 2014, at 8:08 PM, Monty Schumpert <jmschump...@verizon.net> wrote: > >> Josh, >> >> The instruments I’m using are Raytheon ST60 Tridata and Wind/CloseHauled. >> They output the data on an old Seatalk(1) bus which is a Raytheon/Raymarine >> priority protocol for combining the otherwise NMEA0183 data from the various >> transducers. There is nothing in my manuals regarding the version of 0183 >> associated with these devices. I have done a little research, however, and >> found that version 2.30 came out in 1998 and version 3.00 came out in 2000. >> See http://www.nmea.org/content/nmea_standards/nmea_0183_v_410.asp. There is >> a decent discussion of the relationship between Seatalk and NMEA0183 in the >> following article by a German engineer who has attempted to reverse engineer >> the Seatalk protocol (http://www.thomasknauf.de/rap/seatalk3.htm#Sig). From >> those bits of info and the fact that my manuals are dated August and >> September 1999, I would guess that if the corresponding NMEA sentences were >> demultiplexed from the Seatalk bus, they would conform to the 2.30 standard, >> if you can call it a standard! There is another rather extensive document on >> NMEA0183 sentences, structure, etc in http://gpsd.berlios.de/NMEA.txt. The >> way I am using the old instruments to get the data onto the NMEA2000 bus >> really doesn’t involve NMEA0183 directly (in fact there no way to get NMEA >> data from the instrument heads). What I did was to connect the depth, >> speed/temp transducer signals to the tridata head, the wind transducer >> signal to the wind head, daisy chain the two heads together via Seatalk, and >> connect one of them to the Seatalk to Seatalk ng converter. This effectively >> converts the sentences to 2000 format except for the connector. The Seatalk >> to Seatalk ng converter is then connected to the 2000 backbone via an >> adapter cable which Raymarine sells. When I started this project, I was a >> little concerned about being able to bridge the old instrument data to the >> new bus, since the Raymarine literature stated that ST60+ or ST70 >> instruments were required, but I tried it with the old stuff and it worked. >> Realize this is a somewhat roundabout answer to your question, but the whole >> issue is rather convoluted. >> >> Monty >> Scandia >> 1991 C&C 34+ >> Annapolis, MD > > _______________________________________________ > This List is provided by the C&C Photo Album > http://www.cncphotoalbum.com > CnC-List@cnc-list.com
_______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
