How have others people used these ports? Audio Input, Audio Output, Alarm Output, etc...

[camviewer43]

Recently got a Dahua 4K and it has a bunch ports. Audio Input (RCA port) I kinda get...it's for those external microphones right? What do you use the Audio Output (RCA) for? Do you hook up an outdoor speaker? And what kind of protocol can you use to output to that audio port? Or do these cameras not support a protocol to stream to the audio output?

Same question about the Alarm Input and Alarm Output. If I have a computer on my LAN that I want to use to activate that alarm output, how do I do that?

 

[ludshed]

If your cams have both mic and speakers you probably wouldn’t use them. You could hook up an annunciator if you wanted to hear an audible alert upon motion/line crossing etc. without having to turn a monitor or computer/phone on.
Same with your alarm in/out, I’ve used Optex IDS for long range detection in very dark rural properties where it wasn’t in budget to get cabling to outer edges of property. If they had a ptz you can use the signal from it to tell the ptz to take a look at that preset. I’ve also used them to illuminate an led I’ll mount on the side of TVs to indicate “switch hdmi to your camera input, something is moving.”