Datalink failure messages from MLB100

What software level are your IFD540s at?

Confirmed with avionics shop IFDs are 10.1.1 and MLB is at 4.09

Do you know exactly WHICH "failure" message you had?  I ask because sometimes one piece of ADS-B data (like SIGMETS, or PIREPs, or something) can expire before the next set is downloaded.  When that happens, you get a cyan CAS alert that says "Datalink Data Not Rcvd" (DDNR).  But it's not like you lost all of the data.  The DDNR comes up separately for each type of data, which I found confusing at first.  Why would I get a CAS Alert for weather when I clearly had METARs (for example) on the display.

I have come to understand through experience that DDNR is not an indication of failure, it is simply a state of being.  The not-received data will come around again after a few minutes unless you leave ADS-B coverage.

My best example of this is having a long taxi time at an airport that did not have an ADS-B tower on the field.  Basically all of my pieces of weather data expired (and I got a separate DDNR for each one as it expired) by the time I took off.  But once I was in the air for a while, all of the items downloaded and the CAS alert cleared.

The other example I had was a long VFR flight at low altitude in remote terrain, when I was out of coverage (or on the edge of coverage) for an extended period.  Again, once I reached a more populated area, all of the pieces downloaded and the CAS alert cleared itself.

David Bunin

If you're talking about the Alerts page view, I think that it is only real-time data.  For example, if the unit fails, the alert appears.  The duration starts counting.  Five minutes later, it shows a duration of 5 minutes.

If the unit recovers and data is restored, the alert goes away entirely.

So if you see a fault and a duration, the fault is "current" and the duration is how long ago it first occurred.

"Datalink Receiver Fault" is either a wiring problem or a software problem.  I have seen that one on the bench when some equipment was disconnected.  You might try upgrading the IFD to software 10.1.2.0 which was recently released.

David

petersk wrote: I have the same issue with my installation, which has two IDF540s and an MLB100, also a TWX670. I'm getting two (well, three) types of failures: First, I see a yellow 'Traffic Sensor Fault' popping up frequently, although I'm seeing traffic and it seems to be updating in real time. The fault shows every time that an alert is presented... or perhaps the fault causes the alert. I have videos of this happening, you can see those videos here: http://secure4host.net/big/event1.avi http://secure4host.net/big/event2.avi The second fault I get from the MLB100 is a weather coverage fault, the IDF540 draws a screen full of diagonal blue lines across everything, which is very distracting. At the same time I'm still getting depictions of precipitation and the little METAR flags all over the screen. It seems like the weather is coming in fine, but it still has the blue stripes.  I do not get a textural alert on the alert page. Edited to add the image directly: I'm flying just west of ORD, just outside their Mode C ring, so it should be a good coverage area even at 2500 feet, where these shots were taken. Oddly, the blue lines only show on the top 540. I'm not certain that I had the weather display turned on in the settings of the second one... something I need to play with to be sure of next time. I have at times flown around for 20-30 minutes without seeing these blue stripes, other times they pop right up and don't seem to go away. At the risk of piling on, I also see the occasional 'lightning sensor fault' error... all things considered it starts to feel like the interfaces might be a little too sensitive, alerting at the slightest detail, or the I/O system in general is dropping a few bits here and there.

Edited by LANCE - 19 Mar 2016 at 10:49pm

PeterC wrote: I was using the sim just now and the same thing happened. Half of the window was covered with hatched lines but I did not see a datalink fault. Is the sim having the same sw issues as the 540 and will the 10.1.2 fixes need to be applied Or is this just simulated failures. The lines appeared when I zoomed out about 400nm to my destination.