Here is a subject that has, perhaps, been addressed at least partially.
A French sailor, currently at a port in the Indian Ocean
, has problems with the display of AIS
targets by OpenCPN
For testing, installation
- A AIS
transponder "Matsutec HA 102"
- A multiplexer "wireless / USB" Miniplex2
- An Ipad
- A PC with OpenCPN
V4.0 (same problem with O 3.2.2)
The information from the transponder are sent to the multiplexer.
The multiplexer sends its data to the PC via a USB cable
The multiplexer sends its data to the iPad
The attached two pdf files showing the sentences received by the IPad and those received by OpenCPN.
It is found that:
- All NMEA
sentences received by the iPad has a "tag block".
- Only the NMEA
sentences, type AIVDO / AIVDM received by OpenCPN has a "tag block".
The iPad displays AIS targets without problems. OpenCPN not show any.
The French sailor has also made a recording with VDR in OpenCPN. This is the "VDR1.tx" section attachment, download.zip.doc file.
At home, on my Lenovo, with this "VDR1.tx" file, I have no display AIS target.
I made a second file "VDR2.tx" in which I erased all the "block tag". See attached. with this "cleaned file" I have no problem displaying all AIS targets.
It appears that OpenCPN not cleaned all NMEA sentences.
The French sailor saw that it is possible to prevent the presence of "tag block" in the NMEA sentences, the output of the multiplexer, using preferences of this multiplexer.
This should solve the problem partially. This test will be done today.
That said, the real solution would be OpenCPN cleaned all NMEA sentences that have a "tag block" at first.