Disappearing AIS targets

[Jim.Pope]

I am experiencing a similar problem with AIS targets never showing up or potentially disappearing.

System includes (3) e125 displays, each running V19.03 and ICOM M506 with AIS receiver. There is also a RS130 in the mix. All components are interfaced on NMEA 2000 network along with a number of Maretron products. No NMEA 2000 system anomalies except the e125's display of some received AIS targets. No NMEA 0183 connections to any of the equipment.

Similar to Robert's report, i have a PC running Coastal Explorer which is interfaced to the system via an Actisense NGT bridge. Coastal Explorer shows the same AIS targets listed on the ICOM AIS list. On the e125 units, some targets never appear.

We have been cruising with friends for the last couple of months and they have never shown up on our e125 while always showing up on the Coastal Explorer display. This is true whether we are next to each other or separated by several miles.

There are other examples of targets not showing up on the e125 while being present on Coastal Explorer. I simply highlight the one example as it is an example that is consistent and... easily reproduced.

I also suspect that there are cases of "disappearing" targets - although I am less confident of this observation given potential differences in how targets may be prioritized in high traffic areas, in / out of a cache, etc.

If it would be of any help to you, I believe it is possible to record a NMEA 2000 data stream with an Actisense pc tool. That might help determine if there is something in the AIS data that is causing this issue.

Of course, the best answer is that it is operator error and a configuration change on my end would solve the problem!

Many thanks for any help.