COP-USA DVRMPEG4-16LAN - Manual (Page 29)

Attention : The alarm output is TTL high level control. The connection method is described in details in the
picture above.
This DVR can carry sixteen sensor alarm input equipments and four alarm output equipments.
There are two types of alarm input:
Voltage input (5V and 0V)
The low electrical level alarm of DVR is required if the usual voltage output is at high electrical level (5V)
and alarm is set at low electrical level (0V).
The high electrical level alarm of DVR is required if the usual voltage output is at low electrical level (0V)
and alarm is set at high electrical level (5V).
If the sensor outputs low voltage (0V) normally, and outputs high voltage when triggered (5V), then user
must set DVR as high voltage alarm.
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