Using MIMOlite to ARM/DISARM Alarm Panel (Honeywell Vista + Others)

Most security alarm panels out there have the ability to use a “Keyswitch Zone”. This is a zone that when closed will ARM or DISARM the system. On Honeywell Vista panels there is also a built-in relay that will close when the system is armed. I am using a MIMOlite to monitor the ‘Armed Status’ (contact) and to trigger the ARM/DISARM (relay). I have built a custom Device Type that displays and handles this activity.

My question is, can I change the Hub LocationMode based on the contact being OPEN or CLOSED? or will I need to find/make an App that will do that?


I’m assuming you mean Home, Away, Night, etc, etc modes, which in that case you can use a Routine. When you create a new one, and when asked “what do you want to happen?”, scroll down and select “Change mode to”. Then select “automatically perform xxx”. Select “something opens or closes” and pick your contact sensor.

Could you please show exactly how you wired up the mimolite to your security panel?

+1 on how you have this wired up. It’s sounds so simple and brilliant. I really want to get my panel connected in a simple way and this on surface sounds just the job


you made me realize you could do this with an alarm system remote key fob too, just need to hardwire the contact in the remote to a MIMOlite.

I will create a wire diagram tomorrow, in the mean time this is what my device looks like… I can still use a bit of help with the coding if anyone is interested in this project.

Wiring Diagram for a Honeywell Vista20p panel


Many thanks for sharing the wiring diagram, I’m going to match this up to my panel and see if it’s easy to replicate.

Not being an expert on Honeywell configuration, did you have to program anything within the panel or is this zone 8 typically reserved for keyswitch operation?

Thanks for such a great idea.

Try searching Google for “Adding Keyswitch to Honeywell Vista XXX” where xxx is your model number. I’d paste it for you here but there are a bunch of different panels. Basically you need to do 2 things, change a zone type to Keyswitch and program the trigger output for armed. Both are very easy it shouldn’t take more then a few keystrokes.

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Is the mimolite capable of displaying the voltage of the input trigger? I see you have it shown but at 0v.

Yes it is, I am using contact closure for my solution.

I would like to get this installed as I think it’s brilliant but don’t have program access to my alarm panel. That’s all handled by my local vendor who also provides the monitoring.

I wonder if a way forward would be to have them install an official Honeywell Ademco 4146 Vista Keyswitch Arm Kit ($55). I could then hook the wires up to the MIMOlite once they’re done/proved the key switch is working correctly.

Question: @disforw do you think thank will work as it keeps me out of mucking with alarm panel setup???

Thoughts most welcome.

Actually, I happen to work for a National Alarm Company (hence my interest in the integration). Maybe I should set myself up a way to offer remote programming, more personalized wiring diagrams and/or keypad programming instructions for a nominal fee.

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I would love that. If you think it’s possible to config remotely I’d welcome the service

Hi I just moved to a home with the 20p and the setup is excellent. I just want to be able to arm and disarm from smart things. This setup looks perfect for me. Have you written some good instructions on how to do this?

@disforw This setup worked well for you? I would love to set this up. Have steps to accomplish somewhere?

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@disforw, I just came across this thread and would love to try / look at the code / handler for this… Let me know if you have it posted or ping me with it. It is a awesome use of a mimo relay, maybe some enhancement ideas will come to me.

I just hooked up a Mimolite to my Honeywell Vista 20P yesterday with a 4204 relay.
I followed these instructions here
Not bothering with adding a program to Smartthings I only wanted it to do one thing. When I unlock the front door with my Schlage FE599 lock a simple automation in the new app activates the Mimolite and disarms the alarm.
Not looking to arm or do anything else to the alarm with Smarthings so I am happy with the outcome.
The 4204 relay setup prevents it from arming when disarmed don’t want it to arm and disarm all day if you are going in and out of the house.
For anyone that decides to do this, the one thing not documented is that the default momentary latch of the Mimolite is 1/2 second. That is not long enough. I have it at 1.5 seconds now all is good. You have to add the device handler from Fortrezz so that you can adjust this time for the Mimolite.
I did not bother putting a 2K resistor for supervision on Zone 7 so just I just programmed accordingly and chose NO instead of EOL for hardware type for Zone 7.