Alarm Pad with Aqara T2 and dry relay

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Hello,

I am currently exploring the different alarm options with Aqara and I really need a pad with badge for arming and disarming. I was a bit disappointed that currently no one was sold by Aqara.

I think that it may be possible to achieve the same with an badge reader pad that has a dry relay to an aqara T2 module that should then forward the information to the M3 Hub as a switch for arming or disarming ?

There is a plenty of modules like this on Amazon, and I found one at hikvision which despite being a bit expensive would allow configuration over a WiFi web interface and customization of the relays behavior, offering multiple output relays aswell.

The Aqara T2 module seems to support 2 dry inputs, I think would have one for arming and one for disarming.
Arming for the pad would be done with the doorbell button maybe (or a special pin) activating the second relay, I didn’t chose yet I think i need to test what’s best. Maybe I’ll end up having same pin and output for arm and disarm and just not using doorbell button (or for some Aqara special silent alarm mode thing that I saw)… but well, l’m not there yet :).

Here is the Hikvision DS-K1T805MBFWX, that I consider using, module documentation: https://pinfo.hikvision.com/hkwsen/unzip/20231020151141_49449_doc/pdf.pdf

(I put an example of an Amazon one aswell in case some are interested: Amazon.fr)

Has anyone already setup such ? Or just a T2 as dry relay to Aqara for automations ?

Anything I am missing that may make it totally infeasible ?

Thanks a lot for your help

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Hello, if this is a group security alarm (for a house), you will not be able to do this. You need to look carefully in the documentation for one subscriber there are dry contact outputs? As a rule, these are digital security systems, so everything is not so simple here. Also note that the dry contacts of the T2 relay are not disconnected, they have a common COM for two relays.

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3

Hi,

Thanks for your answer, the two products (hikvision or amazon example) are standalone door openers products that have dry contact outputs yes. SO my plan was to link the dry contact to the Aqara t2 to « forward » it as a switch contact to Arm/Disarm in an automation.

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If it’s an individual system, we can fantasize about something. Again, for one house.
You can place the relay in the electromagnetic power supply circuit, so you can combine the two systems.

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Thanks.
That would be awesome if it works as expected. I may try it and will give a feedback. I don’t even have a door to control it’s really just to Arm / Disarm the Aqara alarm with PIN code and/or badges, so yeah I’ll just plug the T2 com to the door magnetic lock COM as dry switch (without adding a power supply). But yes good to mention that for others that have such door system it can be worth putting the Aqara T2 in the middle of the circuit aswell.
Again, thanks, helps me to have someone confirming that on the paper it may works :slight_smile:

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@fvt11 , I described the capabilities of the T2 relay here, you can read its characteristics. Rele T2, let's talk about it again

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7

Why another (additional) relay, you just give another wireless button to another user😊

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Thanks for the link !
I think of many other use case with the wet and dry contacts modes now haha. First will likely be my garage door.

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