Traditional Culture Encyclopedia - Photography major - What are the alarm I/O interfaces and audio I/O interfaces of network cameras?

What are the alarm I/O interfaces and audio I/O interfaces of network cameras?

As the name implies:

1, alarm input and output are used for alarm:

2, audio input is to let the front-end sound through the network cable to the PC, mainly used for sound monitoring, you can listen to the sound when recording.

3. The webcam seems to have no audio output, only intercom output.

4.RS485 is mainly used to control the pan/tilt!