wx500 and ifd540 not talking

I have an IFD540 that was installed along with a wx500 stormscope in 2014. It was working at that time. I have since upgraded the software to 10.2.0.0.A but otherwise the avionics are as they were installed. I live in California, so don't have a lot of times when I would see a lot of lightning activity. At some point it looks like it stopped displaying strike data on the 540. I noticed this on a trip across the country last year. Checking the status LEDs shows everything it is supposed to. TX and RX lights are on and blink occasionally. The other LEDS look correct. However I cannot see anything on the IFD540 config page when looking at the pages that should show information on the WX500 status. Its just blank, no error logs or other. so it looks like it's not talking to the IFD. the WX500 is currently on RS232 port 3. I tried moving it around to other ports in case this had somehow gotten mis-assigned but that didn't help. My question before I take it for service is are there any other configuration settings i should check, for RS232 or other before I do that.

i thought Id post here to let folks know this has been solved, as it may have some relevance to other problems. I took the plane to exec autopilots in Sacramento for debugging, thinking this was an issue with the WX500. the results were interesting. To recap. The status pages from the WX500 on the 540 were inop, however the unit was sort of working. some strikes were displayed on the 540, but I had a storm right next to me in Arizona on a trip back from the east coast with no strikes shown. I also would get occasional Lightning sensor fault messages on the 540. A power drill next to the antenna recently did show some activity as well. However EAP had an ifd 530 that when swapped worked properly with the stormscope, i.e. showed the status pages properly. This suggested the issue was not the WX500. First step was to upgrade the software to the latest rev on the 540. This did not fix the issue. I had to come back for them to try another 540, this did not show status properly either. Since it didn't seem like a WX500 issue or issue with my 540, I asked them to move the WX500 input from com3 to com4. This fixed the issue. WX500 status pages now are visible on the 540. So for some reason com3 is not a good choice for this. EAP was not sure why but com3 is apparently used for cross fill when that is needed, so perhaps it is not a good choice for other uses. This may have some relevance to problems others are experiencing, which is why I am posting this. I am not sure why this wasn't detected at the install, but I suspect it has something to do with the fact that this unit was installed right after the IFD was released by Avidyne, and there have been many software updates since then. Perhaps this failure mode was introduced later on with a new software release. We don't get much T-storm activity in CA which is where I do most of my flying, so this problem wasn't visible most of the time. also it may be that Avidyne recommends not using com3 for other devices. I haven't searched for that on the forum.

Edited by B2C2 - 20 hours 45 minutes ago at 2:07pm