MVP7500,MVP8400 locked up
yanbin
Posts: 86
in AMX Hardware
Recently I am experiencing lots frustration with old MVP7500 and MVP8400, they just keep dropping offline every couple days, clients had to reset them every couple days, and eventually they will be totally frozen. All these panels having same issues had the old wireless network card installed (would not do WPA encryption), and using WAP200 wireless access point. One of the MVP8400 was sent back to AMX for repair, but it still having the issue after repaired. Is anyone having this same issue? Should I change the wireless network card? or WAP200?
Thanks for everything.
Thanks for everything.
0
Comments
When this happens the panels slow down over time until they eventually freeze up and won't even navigate around the setup pages if you can get into them.
The length of time this takes to occur depends on how often they go on and offline (if it's every minute or so they can lock up overnight). A test would be to reboot the panels at, say, 3AM and see if they still freeze after a few days. The fix would be to make their wireless connection more robust, one way or another.
The old wireless card could definitely be a problem. We have had to switch out all of ours and have had much better results with them. Wireles networks are pretty much a black art. I'd get a Spectrum analyzer if I were you. they also help out greatly.
Two suggestions: (1) turn off an and all 802.11N in the location; the N handshake seems to scramble the AMX wireless cards, it tries to handshake with it and fails if it is present at all, even though they don't even try to be compatible; (2) make sure your access points don't have the trendy new "automatic channel" feature activated. It's only good for when you first turn the unit on, and transient noise might make its choice unusable long after it commits to a channel.
One other issue that will cause problems as I have recently discovered is a noisy environment. And by "noisy" I don't necessarily mean something that will show up on the Wi-Spy spectrum analyzer. My recent trouble-shooting at a site showed that a panel can have a lot of problems with little interference detected. I'm still not quite sure the root cause but I suspect it is reflection from surfaces within the structure (cement walls, metal in the walls, WAP surrounded by metal pipes, WAP installed in a metal box -- don't laugh, I actually saw this, etc).
So what the panel sees is an environment with a ton of retries required. This causes a lot of thrashing in the firmware of the wi-fi card (something AMX cannot control as this is a 3rd party card). We have seen instances where the card can get confused enough that it stops sending anything out. The only recovery mechanism is to reboot the card, which unfortunately requires rebooting the panel. We have found a way to prevent this by playing some tricks in the wi-fi driver and are in the process of testing this fix out. I'd expect this to be out in the next month or two.