Hi, just set up new system with only 4 cameras. Three of them are PTZ with two cameras - one fixed and one with ptz (model number: DS-2SE7C144IW-AE). I have both the fixed and PTZ cameras as seperate inputs on the NVR (model number: DS-7732NI-I4 / 16P(B)). One of the cameras keeps on giving an exception alarm every 30 minutes (exactly) of "Network Disconnect" on the PTZ input stream only. None of the other cameras do this. This camera is hardwired back to the NVR. The very strange thing it was up and running for a few days with no errors and yesterday it just started with this exception every 30 minutes. The fixed camera which is on the same unit does not give an exception. There is no difference in the configuration of this camera from the others. Any ideas? Thanks.