I am trying to add exisitng UNIVision camera to  VIGI NVR , however it is not detecting them, I could not see anything on Device found and Device detected screen. I tried to search through plug and play, however none of the four cameras were detected. I  also tried to add them using  add manually, however I was not successful, as I do not know the IP address. Please support me so that I can set the camera.