14
4.3RS485 port connection
If you want to control pan-tilt, lens and process the relay of the alarming signals by the DVR, the 25-pin RS485 connection can
realize. RS485 connection can control various pan-tilt decoders, and the specific type of the decoder can be selected from the
Control of the System setting in the menu. On DB25 plug the foot
’
s serial number is marked. The definition of the foot is as
following
（
The broken line in the graph means being connected inside.
）
a)
1
、
14
、
2
、
15
、
3
、
16
、
4
、
17 connects to alarm input: ALARM1~ALARM8
；
b)
5
、
18-OUT1
，
6
、
19-OUT2 two linked normally open output:
c)
7
、
20-OUT3 are two attached inner lines
，
either foot is contro12V output
；
d)
8
、
9
、
21 are +12V power output, able to be taken as the power supply for alarm sensor
；
e)
either foot of 10
、
22 is the B line of RS485, either foot of 11
、
23 is the A line of RS485;
f)
12
、
13
、
24
、
25 are earth lines.
Combined as RS485 B line
Combined as RS485 A
line
Decoder
Decoder
A B
A B
Alarm input ALARM1
┆
┆
ALARM8
Alarm output
ALARMOUT1
ALARMOUT2
Contro12V output
+12V output
Earth line
120
Ω
resistance
（
suggested
）
