Whether NVR and IPC in the same LAN, whether IP address of NVR and IPC are in the same network segment ( such as IP address of NVR 192.168.1.18, the IP address of IPC must be 192.168.1.xxx).

After determining the above conditions, NVR supports 720P or 1080P pixel specifications of, NVR with 1080P specifications can pick IPC 2with 00W/130W/100W pixels, can not accept the IPC with higher definition tahn 300W specifications; NVR with 720P specifications can pick IPC with 130W/100W pixels , and can not accept IPC with higher specification than 200W pixels.
  If these settings are correct, then it also can not display, verify whether IPC are bought from our company, if not, please provide the IPC to do compatibility with NVR.