This relay can be controed by keyboard , if use item in the DVR directly, the DVR need to support wiper/Auxiliary lighting function.

2 way Relay switch output, 64 addresses Available
Three 12v voltage amount, positive or negative convertible
Can be used to control the camera zoom, focus.
Such as aperture, wipers or lights
485 can also be used to control other devices
Features:
Compact and easy to install
Two-way switch output
Three 12v voltage output
RS-485 communication
You can set the address and baud rate
Compatible PELCO-D, PELCO-Pprotocol
Technical parameters:
Operating voltage: DC12V
Communication: RS485
Protocol: PELCO-D/P (automatic identification)
Baud Rate: 2400,4800,9600 can be set
Address: 64
Switch: two-way normally open
Relay Power: AVC270V / 10A; DC125V / 12A
The amount of output voltage: three 12v voltage output, plus or minus convertible
Output Current: 800mA
size:76*45mm
Temperature: -10-50c
Humidity: 10%-70%RH