Hi Paul. Thanks again for the the help so far. Was great to finally visit and see the full range on display in the shop.
I've built the setup on a test bench. It works great apart from the echo / talkback. I'm using the normally closed relay on the VoiceOff to route the audio back into the DVR and it just gets caught in a loop of switching on and off. Even the sound of the relay clicking is enough to cause an echo!
The problem seems to be that the DVR audio out includes whatever enters the audio in as soon as the mic icon is selected on the app. Is there anyway to configure it so that it's audio out only comes from remote talkback? The speaker icon on the app doesn't seem to do anything, instead the mic button enables two way audio. I assumed that the speaker would toggle audio in and the mic would toggle talkback?
Thanks
Dale