Hi Matt,
The DVRs are Standalone. Most of them have same symptoms. No, they are in clean and Air Conditioned Control room. They are just locking up, no error displays.. nothing. When DVR is working fine and all Alarms connected, it gets hanged after a while or a day. Hanging means, it doesn't hang the whole system. it still shows the monitor with real time view (people/car moving), but we will not have any control over it. like we will not be able to control with the Keyboard, cannot playback, no TCP/IP connection, date and time freezed... All these happens till we restart the DVR. then it will work normal for sometime/day. Again Hangs!!!!