IPVMU Certified | 07/23/13 06:07pm
The initial intent of SD cards from the point of view of most manufacturers was to have a backup location for recording video if the NVR went offline, or just to have somewhere to store images if there was no NVR. Having the camera either load video from the card to the NVR when the NVR came up again, or having video transparently available in the NVR's software interface on playback is a more involved development and is only a recent offering in some systems.
I confirmed with DW too that they cannot yet have video on the SD card transfer or transparently available for playback in their new DW Spectrum (NetworkOptix) software, but it's in devlopment and in the industry will probably be more the norm soon enough, at least for any VMS or NVR system that wants to keep up with innovation.
IPVMU Certified | 07/23/13 06:09pm
I forgot to mention I got to inquire about this because we recently installed some DW cameras for testing along with their Spectrum software.
Thanks for your assistance Luis.
A few manufacturers, like Bosch, provide the abiliity to rebuild lost video back onto NVR from SD Card. Most manufacturers SD card interface record in AVI files which can be viewed/downloaded through the cameras browser interface over LAN/WAN. It is pretty impractical to have to physically retrieve the SD card to recover lost video.
Genetec and Milestone also support this type of "trickling" with Axis and some other cameras.