Camera Inputs; Rs-485 Port - GE TruVision DVR 20 User Manual

Alarm out number
Alarm out 2
Alarm out 3
Alarm out 4
Figure 3: Alarm output relay in idle state

Camera inputs

Connect cameras to the TVR 20 using 75-ohm video coaxial cables with BNC
connectors. There are two BNC jacks for each camera. Either jack can receive a
camera signal. The signal is looped (directly connected to the other jack), making the
camera signal available to other equipment.
The camera input connectors are auto terminating. This means that the input signal
will automatically be terminated with 75-Ohms unless a second cable is connected to
the second BNC connector of the same camera input.
Make sure there is 75-Ohm termination at the end of the video line if the signal is
looped through the TVR 20.

RS-485 port

The RS-485 port is used for pan, tilt, zoom control of PTZ cameras as well as for
keypads. See "RS-232 and RS-485 port settings" on page 96 to configure this port. See
Figure 4 on page 10 for the serial pin outs for the configuration.
TruVision DVR 20 User Manual
Pin Description
1 NO (Normally Open)
2 C (Common)
3 NC (Normally Closed)
1 NO (Normally Open)
2 C (Common)
3 NC (Normally Closed)
1 NO (Normally Open)
2 C (Common)
3 NC (Normally Closed)
49BChapter 2: Installation
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