LONG Building Technologies | 12/19/14 06:33pm
We used to do this frequently for analog systems, and had good success with KVM equipment from BlackBox. The particular components will depend on the exact requirements. A similar system with DVRs involved 2 monitors at the front desk, 1 mouse & keyboard, 2 video extenders, 1 KVM extender, and 1 KVM switch. This allowed both DVRs to be monitored all the time, and alternate control of each for screen configuration or investigation. Also local KVM at the DVRs for configuration and service.
I have to say, though, that I am happy that most of these systems have been upgraded to IP now and we don't have to support these installations, because they were often a pain to troubleshoot if something stopped working, which happened several times over the years.
We've successfully used RS485 for remote keyboards and VGA-to-UTP converters to remotely view and control a couple of Everfocus DVRs in a remote location. Everfocus makes an optional RS485 keyboard/joystick, which is what we used for control. I assume at least some other DVR manufacturers also have remote joysticks.
With many DVRs, you can remotely access multiple units via a network and appropriate software, too.
sorry - have never done something alike in cctv, but have a simular experience in general computing.
for monitor, you can use frequency converter, to shift signal from low-freq tv signal (~4mhz) to broadcast tv (~100mhz). If your dvr are outputting vga - there are vga to tv converters. And you can deliver both video with a single coax, observing on two tv-screens.
as for mouse, thats depends. You can either use rs232 to rs485 converters, or usb to fiber. In our modern world, never knows what is better:)
Check out Hall Research. They have KVM switches that use CAT5/6 for up to 500 feet. I have used them successfully on IP systems. They don't play much in the security market but AV guys know them well.