Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 06-05-2012, 01:50   #1
Registered User
 
FWallenwein's Avatar

Join Date: May 2012
Location: Germany
Boat: Felz Scorpion II, 11m
Posts: 3
OpenCPN and external NMEA0183 alarms

Hi Folks,

I'm looking for a way to somehow feed external alarm conditions to OpenCPN via NMEA0183, and to display or even acknowledge this alarms.

Let me explain what I'm looking for.

I have some seatalk instruments, that can emit alarms.
Things like "Depth transducer defective", "Wind shift alarm"," Radar monitoring alarm", "gps failure" etc.

I have built a multiplexer with bridge function, that converts seatalk data into NMEA. This NMEA data are than feed to openCPN.
That works well with "normal" data and "normal" NMEA sentences. Things like depth, speed, postion, waypoint ....

But now I'm looking for a NMEA sentence, that represents different alarm's.

It would be great, if openCPN could display this external alarms and maybe even offer a button for alarm acknowledge.
The acknowledge could be sent from the PC to the converter and back to the seatalk devices.
This would require another NMEA sentence for alarm ack.

- Does anyone know of a "Alarm-Nmea-Sentence" and a "Alarm-Acknowledge-Sentence" ?

- If we should find such a sentence - any Ideas on how to implement this functions into openCPN ?

- Would something like that be interesting to other OpenCPN users ? Or am I the only one who would like have it ?

Thank's for any ideas.

Frank
__________________

__________________
FWallenwein is offline   Reply With Quote
Old 06-05-2012, 02:49   #2
Registered User

Join Date: Feb 2010
Location: On the go. Not in Prague.
Posts: 4,016
Re: OpenCPN and external NMEA0183 alarms

Frank...
It seems there used to be PNATD sentence created by old versions of the "official" Seatalk-NMEA bridge (http://www.busse-yachtshop.de/pdf/se...-interface.pdf, but as usually there's nothing more than that the sentence exists) - in the recent Raymarine docs you won't see it mentioned anymore.
You will probably have way more luck doing it with ALR/ACK as used in some other applications, the following taken from AIT250 manual:
Code:
AIS Alarm Messages (NMEA 0183 ALR, Text)
ALR message format
$--ALR,hhmmss.ss,xxx,A,A,c--c*hh<CR><LF>
Where
 hhmmss.ss = Time of alarm (UTC)
 xxx = Unique alarm number
 A = Alarm condition
 A = Alarm acknowledge state
 c--c = alarm description, text
Alarms descriptions presented are:
 AIS: TX malfunction
 AIS: Antenna VSWR exceeds limit
 AIS: Rx channel 1 malfunction
 AIS: Rx channel 2 malfunction
 AIS: general failure
 AIS: no sensor position in use
 AIS: no valid SOG information
 AIS: no valid COG information
 AIS: 12V alarm
 AIS: 5V alarm
 AIS: Loss of serial interface integrity
 AIS: Background noise above -77dBm
ACK messages
Can be generated by a minimum keypad and display (MKD) unit, chart plotter or other display device connected to the SRTMTB
to acknowledge an alarm condition reported by the SRT-MTB.
ACK message format
$--ACK,xxx*hh <CR><LF>
Where
 xxx = unique alarm number
Implementing reading such a sentence and doing whatever based on it's contents in a plugin will be close to trivial. Data output less so until we will have a revamped serial I/O infrastructure and API in place.

Pavel
__________________

__________________
nohal is offline   Reply With Quote
Old 06-05-2012, 12:39   #3
Registered User
 
FWallenwein's Avatar

Join Date: May 2012
Location: Germany
Boat: Felz Scorpion II, 11m
Posts: 3
Re: OpenCPN and external NMEA0183 alarms

Quote:
Originally Posted by nohal View Post
Implementing reading such a sentence and doing whatever based on it's contents in a plugin will be close to trivial. Data output less so until we will have a revamped serial I/O infrastructure and API in place.
All right. Thank you for the info.
I guess I'll start trying to make a plugin using the ALR/ACK sentence.
ALR at first, ACK woud require NMEA output.

I think it would be nice to use the alarms from the instruments and use the alarm settings made in the instruments.

Looking forward to read about news regarding revamped serial I/O infrastructure in the future.

Thank's
Frank
__________________
FWallenwein is offline   Reply With Quote
Old 06-05-2012, 16:31   #4
Registered User

Join Date: Feb 2010
Location: On the go. Not in Prague.
Posts: 4,016
Re: OpenCPN and external NMEA0183 alarms

Frank...
Have a look at the NMEA stuff in the dashboard plugin - will get you half way without any effort... Another cannibalized version of it with less code around in https://github.com/nohal/survey_pi

Good luck

Pavel
__________________
nohal is offline   Reply With Quote
Reply

Tags
opencpn

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 19:52.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.