I am an end user/owner of a Schneider Electric access control system. We have recently (within the last month) had three ACX5740 door controllers fail, all in the same manner. Basically the unit appears off line in the system, door access is not functional, unable to communicate. All LED's appear normal, units still respond to a PING, but I was unable to get them to return to Online status. I first attempted the RAM clear, no luck. I then performed an IP reset, unit will still respond successfully to a PING, but I am unable to connect to the configuration page through a web browser even when plugged directly into my laptop. Any suggestions you can offer regarding how to fix this issue, and what may cause this to happen, would be greatly appreciated.
You should probably contact your local SE office or EcoXpert and book a service visit. One failure can be seen as bad luck, but three makes me think it's something related to the environment or installation.