GeoVision GV-AS2120 IP Control Panel - Manual (Page 159)

The Web Interface
157
8
=
4
7
Figure 8-9
[Interlock]
When the option is enabled, the two mentioned doors will be interlocked,
allowing only one door to be opened at a time.
Note:
1. The Interlock is not supported by GV-AS1010 / 1110.
2. The Interlock is not available on the Web interface of GV-210 / 2110 / 2120 / 410 /
4110 / 810 / 8110, but you can access the function for these models on the Controller
Setup page of GV-ASManager.