Maxtor QSNDVR9M - Manual (Page 27)

2.6 Alarm cable connection
Example of alarm output connection:
Attention: The alarm output is TTL high level control. The connection method is described in detail in the
Above picture.
This DVR can carry sixteen sensor alarm input signals and four alarm output signals. There are two
types of alarm inputs: types of alarm inputs:
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.
Open/Close input
N.O: Normal open. It will be closed when triggered. DVR must be set as low voltage alarm;
N.C: Normal close. It will be opened when triggered. DVR must be set as high voltage alarm.
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