Depending on the DVR you have, will determine the quality of the displayed image. Most low end DVR's will display recorded image and medium to high end will record the images and loop through a live feed to the viewing monitor.
To answer your question about obtaining live view, I will need to know the following.
1. Does the DVR have two BNC connections for loop in - loop out?
2. Is the monitor VGA or composite, if composite, does the monitor have a passive loop in - loop out connection?
Bookmarks