As installed and tested with a Mercury panel. The second, third and fourth doors on the same I/O device repeat the pattern on inputs and relays 2–4.
Program it to pulse on "access granted" for that door. Not the lock or strike relay, which also fires on request-to-exit and held-open.
Every signal crosses a relay contact, so the panel and the I/O device stay electrically separate. Their grounds don't need to be joined.
Set the panel input as a normally-open alarm point, with the end-of-line resistors your input configuration uses.
PassMatch only watches and reports. It never decides whether a door locks or unlocks, and it is wired so it can't.
Exit hardware, request-to-exit and fire-alarm release are not connected to it. People leave exactly as before.
If the PC, camera, I/O device or network stops, doors and access control keep working normally. You only lose the tailgate alarm, and the monitor reports the device as down.
12–24 VDC signal circuits through relay contacts rated 1 A. No mains wiring at the door.
No video leaves the camera, and nothing is stored but counts and times.
| Door circuit | Connected? |
| Lock / strike / maglock power | No |
| Request-to-exit (REX) | No |
| Fire alarm door release | No |
| Panic / exit hardware | No |
| Door position contact | No |
| Spare AUX relay (listen only) | Yes |
| Spare alarm input (report only) | Yes |
Install by a qualified installer to the panel maker's instructions, local codes and the authority having jurisdiction. Use spare panel points only.
Overhead or angled at the door, "crossline counting" scenario. Tested with the Axis P3288-LVE.
Raspberry Pi 5 with stackable relay boards: each board has 4 dry-contact inputs and 4 relays, so 2 boards cover 8 doors. Or an I/O-to-network device per 4 doors.
One auxiliary relay (access granted) and one alarm input (tailgate).
Any always-on Windows PC, or its own Raspberry Pi with a screen. No internet connection needed.
A water probe and a temperature and humidity sensor per room, on the unit's spare input.
Standard low-voltage installation materials.
| Alarm time | Under 1 second from the person crossing |
| Doors | Up to about 8 per unit, any number of units per mother |
| Delay per door | Set per door, e.g. 5–15 s |
| CPU | Under 1% of one core at 100 busy doors |
| Memory | About 35–40 MB |
| Network | About 1 KB per badge or person |
| Internet | None |
| Event history | Kept 90 days by default (adjustable) |
| Ports (local only) | 8080 I/O devices · 1883 cameras · 8081 web page |
We can install PassMatch on a single door alongside your existing access control, with no changes to how the door works, and show you the tailgates it catches.
