Installation and Configuration
6
2.3.3 Alarm Output – Switch Application
The alarm output drives the external circuit, with a maximum current of 30 mA and a maximum
voltage of 5 V. It is recommended to add a relay if the circuit exceeds the maximum values.
Figure 2-6: Alarm Output Switch Application Diagram
Locally Storing Data
Certain cameras include a SDHC card slot for onboard storage that support a 128 GB Micro
SD card. Dahua recommends using a SanDisk Extreme Micro SD card (or an equivalent
substitute) as these cards have been fully tested without issue and the SanDisk Extreme line
is better suited for constant recording. Lower-grade SD cards meant for multimedia
applications will, at times, have questionable quality and reliability.
Recording to the SD card is first in first out (FIFO). The camera deletes the oldest (first) entry
as new storage requirements arise. The camera does not signal nor make an indication when
data is deleted. Storage time is dependent on a variety of factors such as SD card size, image
resolution and video frames per second.
SD Recording supports video only. Audio is not supported.
