Vivotek ND9542P 32-Channel 4K UHD NVR (No HDD) - Manual (Page 191)

VIVOTEK - Built with Reliability
User's Manual - 191
When you find something of your interest, use the Export function to export a
video clip.
Select the length of the video clip using the Start and Stop time menus below.
Depending on the length of clips, an export can take a while to finish.
The default export length is 30 minutes.
Note that for specific cameras, such as fisheye cameras, you can click its view cell to display
its control options such as the dewarp type.