9 rs232 – IC Realtime Combo Series: 8 Channel DVR with built-in 19 LCD monitor User Manual
Page 29
 
20
z
3 ways relay alarm output (NO contact). Provide external power to external alarm device.
z
To avoid overloading, please read the following relay parameters sheet carefully.
z
RS485 A/B cable is for the A/B cable of the PTZ decoder.
Relay Specification
Model:
JRC-27F
Material of the 
touch 
Silver
Rated switch capacity
30VDC 2A, 125VAC 1A
Maximum switch power
125VA 160W
Maximum switch voltage
250VAC, 220VDC
Rating
(
Resistance
Load)
Maximum switch currency
1A
Between touches with same 
polarity 
1000VAC 1minute
Between touches with different 
polarity 
1000VAC 1minute
Insulation
Between touch and winding
1000VAC 1minute
Surge voltage
Between touches with same 
polarity 
1500V (10×160us)
Length of open 
time 
3ms max
Length of close 
time 
3ms max
Mechanical
50×106 times (3Hz)
Longevity
Electrical
200×103 times (0.5Hz)
Temperature
-40℃ ~+70℃
3.9 RS232
You can connect the combo DVR with POS or Keyboard through RS232. 
With POS system, the combo DVR can communicate through RS232 and network. For the POS 
system, the combo DVR can integrate the text content and even search the record through the info. 
The series combo DVR also supports NKB operation. You can operate the combo DVR from the 
keyboard controls instead of using the control pad on the front panel of the unit. 
To connect a NKB keyboard to the combo DVR: 
1. Assemble the KBD keyboard according to the instructions in its accompanying installation manual. 
2. Connect the KBD keyboard into one of the RS232 ports on the combo DVR or through network. 
3.10 RS485
When the combo DVR receives a camera control command, it transmits that command up the 
coaxial cable to the PTZ device. RS485 is a single-direction protocol; the PTZ device can’t return any 
data to the unit. To enable the operation, connect the PTZ device to the RS485 (A,B) input on the 
combo DVR. See 
X289H289H289H
Figure 3-9.
Since RS485 is disabled by default for each camera, you must enable the PTZ settings first. This 
series combo DVR supports multiple protocols such as Pelco-D, Pelco-P. 
To connect PTZ devices to the DVR: 
1. Connect RS485 A,B on the DVR rear panel.