i suggest you to not believe anything what is shown in a youtube video. these people are mostly stupid as hell, only test a few things and sometimes are paid for reviewing a product. if you ask them deep in comment, they dont answer or say "i dont have the product anymore,..." "didnt test it" ... whatever.
i am talking about this :
View attachment 99191
title: the one doorbell to
do it all
but cannot answer call on HA ... haha...
View attachment 99192
........
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here is a thread about the dahua intercom devices.. you can try to ask there ... there are people who have these devices and may can answer your questions.
its just MY personal opinion. i ordered the dahua device and send it back because i was not happy with it.
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if you plan to use the display, you dont need a chime. it has a ringtone and you can also add a external chime to the display.
hikvision has a standalone mode on kv6/kv8 series, so you dont need a display. but you cannot add a chime to the outdoor station... and there is no device available which can be a network chime or whatever. it is a bit stupid... you only have the app available ... not sure what hikvision was thinking about the "standalone mode"-solution. maybe they will update the firmware and will implement a link to one of the two available relais ... would be nice
if you dont need a display i would buy a normal "smart" doorbell.. less problems, but no POE