10
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 3-5
3.4 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.
