The PC interface

The device that interfaces these alarm boards with my server, and my phone, is the Zooz Zen17 Universal Relay.

I chose this to interface with my Z-wave network, a low power short range 900MHz wireless network for home automation. This device is also very cheap (considering the amount of I/O and the general cost of Z-Wave devices) and can run on 12-24V DC as well as USB power.

Installed next to the UPS and interface boards, it was easy to integrate. Set up the Zen17 as such: separate the inputs from outputs (so inputs do not trigger relays), and change the inputs from generic IO to Smoke/CO alarms (this only really changes the labels in monitoring software, but it's convenient.) Run the NO wires from the signal board relays into the S1/S2 signal inputs on the Zen17, and the COM wires to the "C" (common) input next to them. Finally, ran 12VDC power from the UPS (using the second installed barrel jack) for steady power.

[pics of all 3 boxes next to each other and wired up.] [Close-up of relay box IO.]

I use HomeAssistant to monitor and control my Z-wave network, so I used the Z-wave integration to set up alerts to my phone (NOT emails, just app notifications) when the inputs go live.

In HA, set up automations (start blank):

Trigger:
  - type: Device trigger
  - device [choose the dual relay box]
  - Trigger: "Smoke Alarm Becomes Hot"/"CO Alarm started detecting gas" [choose 1]
  - Duration: 1 sec
  
Action:
  - type: device
  - Device: [choose your phone]
  - Action: Send Notification
  - Message: "SMOKE/CO ALARM HAS ACTIVATED!!"
  - Title: FIRE ALARM

If you did not change the input labels, the trigger will be something generic like "input S1 has activated", but the rest will be the same.