AIS is not displayed

[Noitsnl]

Hello community.
I've installed v. 5.0 with all plugins o/b a cruise ship and i use as a secondary ecs (company has payed for another ECDIS).
Currently my opencpn receives SIMRAD 4G through ethernet, FURUNO GP170 GPS through ethernet, GYRO compass data through serial (9-pin) port and AIS through USB. All above data are also forwarded to another pc.
The problem is that from time to time (every 4 to 8 hours) the AIS stops appearing on the application.
The usb port remains active-checked with another app.
The nmea debug window of opencpn shows that ais data are still comming.
Best of all is that all ais data are still shown in "ais radar view" plugin but not in main app.
Most of the times a restart of the pc fixes the problem, but i want to move on from that.
Any suggestions/ recomendations?
Thanks in advance

[CarCode]

Do you want to liften the secret which operating system you are using?

[Noitsnl]

Originally Posted by CarCode

Do you want to liften the secret which operating system you are using?

Off course!!
I missed that..
I run win 7 prof. 64 bit
PC carries intel i5-2400 @ 3.1G, with 4GB RAM
Graphics on-board

[CarCode]

I cannot say too much about Windows because I use macOS.
One reason could be the ais-radar-view plugin eats the data.
So try to use your system without this plugin for some times.
After all I have never used it because the AIS data shown directly on the chart with OpenCPN or firing up the AIS list is sufficient for me.
Does the data shown in OpenCPN stopps for you only in the chart view or also in the list view?

[Hakan]

Noitsnl...
I've more or less the same set-up though on Win10 and Navico 3G and have run it for days.
The AIS-radar plugin I've never used so no experience from that. Although unlikely it would disturb OCPN itself it would not harm much to deactivate it for a test? (I don't see any benefits from it my self?)
You say the incoming AIS is still continued in the NMEA debug window but not visible on chart screen, correct?
What about the other PC? I suppose it receives all data via wlan USB from the first PC. Correct? If so, what about the AIS targets on that screen. Still visible, or not?

[Hakan]

Noitsnl...
I've been running an XP using O v5.0 for 14 hours now wo trouble.
I've used wlan for nav data and AIS feed. AIS targets count about 800 all the time.
So I'd say nothing in XP and O v5.0 will cause the on screen AIS targets to hide.

I haven't tested serial ports data feed though but from your description data was still flowing in to O and further to other system?

BTW, what's your O version?
Håkan

[bcn]

OP said:

I've installed v. 5.0 with all plugins o/b a cruise ship and i use as a secondary ecs (company has payed for another ECDIS).

[transmitterdan]

The first step would be to disable all plugins and run for 8 hours. See if AIS targets disappear.

Then enable the Simrad radar plugin. The Simrad based radar plugin also shows AIS targets. Run that for a day and see if targets disappear. If they disappear notice whether they disappear from both the chart window and the radar display. Wait for at least an hour before shutting down. After that hour do all AIS targets disappear or do some reappear?

Then look at the AIS list by right mouse click in the chart window and select AIS target list. If AIS targets are shown select one and then center the chart on it by clicking the center target button. Does the target appear at chart center where before it was invisible?

[Coquina]

Open the NMEA debug window with logging and post the results. It should be apparent at that point what is going in.

[Maelruan]

AIS Message 27 not displaying on OenCPN 5 chart on Win 10 PC.
Messages of type are received on 156.775 & 156.825 mhz rather than 162~, and are for long distances, incl satellite. Some dongles can be configured for all 4 AIS channels, but I just tune either the higher or lower couple. With the lower 2 selected aisdecoder 3.5.149 decodes Msg 27 and sends the raw message to OpenCPN 5 where it shows up raw on the debug window, but not decoded on the chart. Apparently this message type at 96 bits is shorter than the others which are 128 bits (I think) to allow for longer decoding time over distance, they say. It does not include it's own time stamp, and this should be supplied by the decoder, so maybe this is where I'm having difficulty with OpenCPN. All other messages, received on 162~mhz, display correctly.
Any solution?

[transmitterdan]

Originally Posted by Maelruan

AIS Message 27 not displaying on OenCPN 5 chart on Win 10 PC.
Messages of type are received on 156.775 & 156.825 mhz rather than 162~, and are for long distances, incl satellite. Some dongles can be configured for all 4 AIS channels, but I just tune either the higher or lower couple. With the lower 2 selected aisdecoder 3.5.149 decodes Msg 27 and sends the raw message to OpenCPN 5 where it shows up raw on the debug window, but not decoded on the chart. Apparently this message type at 96 bits is shorter than the others which are 128 bits (I think) to allow for longer decoding time over distance, they say. It does not include it's own time stamp, and this should be supplied by the decoder, so maybe this is where I'm having difficulty with OpenCPN. All other messages, received on 162~mhz, display correctly.
Any solution?

Post a VDR recording with these messages. Then we can check how OpenCPN handles it. VDR plugin will record all NMEA messages even if OpenCPN does not decode them.

[Maelruan]

Many thanks. I'll get a VDR recording when I'm on board in the next day or two.

[Maelruan]

Attached is a screen grab showing, on the left, Aisdecoder receiving and decoding type 27 messages, and on the right OpenCPN debug window with the same messages raw, Txt file with these messages also raw, and the AIS target list blank with no messages decoded. There are no targets shown on the chart behind those windows. The attached AIS_Msg27Test is the .txt file shown on the image.

[transmitterdan]

Thanks for the data. I will look into it.

Is a Type 27 message common at sea from a VHF AIS unit or is it found only when looking at internet streams?

[Coquina]

Message 27 is for satellite AIS.
See https://navcen.uscg.gov/?pageName=AISMessage27
Does OPENCPN read these?
Is there any such thing as an AIS unit that only sends 27 and not the normal AIS A or B messages?