25
Pin Connections for COM Port and Alarm Block
PIN 1. RS232-TX : RS-232
RS-232 Transmit Data Pin. The DVR can be controlled remotely by an external device or control system,
such as a control keyboard or PC using RS-232 serial communication signals.
PIN 2. RS232-RX : RS-232
RS-232 Receive Data Pin. DVR can be controlled remotely by an external device or control system, such as
a control keyboard or PC using RS-232 serial communications signals.
PIN 3. VIDEO LOSS
When video loss happens, it will send a signal to trigger another accessory.
This pin output becomes “Low” when video loss occurs, and remains “High” under normal operation.
PIN 4. SWITCH OUT
Connect to VCR trigger recording terminal of multiplexer, in order to synchronize recording signals. The
default mode is falling (Negative) Edge.
PIN 5. ERROR OUT
When HDD errors happen, this pin will send a signal out.
This pin becomes “Low” when HDD errors occur, and remains “High” under normal operation.
PIN 6. REC START
This pin can accept an external trigger signal to activate record mode from an external device. When the
external signal turns to “Low”, it will trigger DVR record mode. When the external signal goes back to “High”,
it will stop recording.
PIN 7. EXTERNAL ALARM NC (Normally Closed)
Under normal operation, NC is connected with COM. When an alarm is triggered, COM disconnects with NC
(becomes open) for the duration of the alarm. (Form C Relay)
PIN 8. EXTERNAL ALARM NO (Normally Open)
Under normal operation, NO is open with respect to COM. When an alarm occurs, NO is connected to COM
(becomes closed) for the duration of the alarm. (Form C relay)
PIN 9. GND
(GROUND)
PIN 10. RS485-B
The DVR can be controlled remotely by an external device or control system, such as a control keyboard,
using RS485 serial communications signals.
PIN 11. RS485-A
The DVR can be controlled remotely by an external device or control system, such as a control keyboard,
using RS485 serial communications signals.
PIN 12. DISK FULL
Under normal operation, this Pin remains “High”. When the hard drive is full, this pin will provide a “Low”
trigger state.
This may be used to trigger a second DVR to begin recording when the hard drive has filled.
PIN 13. ALARM RESET
When this pin
( PIN 13
) is connected
to
GND ( PIN 9 )
, any alarm notification (Buzzer, LED) on the DVR will
be reset.
PIN 14. ALARM INPUT
When this pin
( PIN 14 )
is connected to
GND ( PIN 9 )
, the DVR will start recording and the buzzer will be
on.
PIN 15. COM
Under normal operation COM connects with NC (Pin 7). When the alarm is triggered, COM disconnects with
NC, and connects with NO. (Form C relay)
