Can your intercom open the door and the elevator?

Key takeaways

• Keep the access control system (ACS) as the source of truth. The intercom asks for an unlock and the ACS performs it and logs it.
• Per-unit identities (a virtual card or user per suite) tell you which resident let someone in, not just that "the intercom" did.
• Elevator floor release works best as an ACS access level, not as extra wiring from the intercom.
• Floor-lockout relays are normally wired so a failure enables the floors, and the lockout must never interfere with fire recall.
• If the ACS has a cloud API (for example PDK or Brivo), you can integrate with no extra wiring at the door.

How it works in 4 steps

1. A visitor calls a unit from the entrance (panel, tablet or QR code).
2. The resident answers and taps unlock.
3. The intercom asks the ACS to grant access, through a relay input, a Wiegand card number or an API call.
4. The ACS unlocks the door, and for elevator buildings it enables the resident's floor for a set time, then logs the event.

The problem: two systems, one door

Many buildings in the US and Canada run an intercom (an "enterphone" in much of Canada) next to a separate card-access system. When they're wired together in the simplest way, the intercom fires the door strike directly, and that causes three problems:

• No useful audit trail. The ACS either sees nothing, or sees a generic "intercom" unlock with no unit attached.
• Security gaps. If the release wiring or relay is reachable from the street side, someone can short it and bypass both systems.
• Elevators stay locked. A visitor gets through the lobby door, but can't get to the floor they were invited to.

Method 1: Dry contact into an ACS input

What is it? The intercom's door-release relay (a dry contact) is wired into an input on the access control panel instead of directly to the lock.

The ACS maps that input to "unlock front door" and applies its own unlock time. The intercom only needs to send a short pulse, so the intercom's relay timer and the ACS's unlock timer don't conflict.

• Good for: existing intercoms where you're adding remote release.
• Audit trail: usually a single "intercom release" event. You know the door opened from the intercom, but not which unit released it.
• Watch for: keep the relay and its wiring inside the secured enclosure, and never at the entry panel.

Method 2: Wiegand "virtual card" per unit

What is Wiegand? Wiegand is the long-established wiring standard that card readers use to send a card number to an access control panel (HID: Understanding card formats). Many intercoms can output Wiegand, either built in or through an add-on module (2N: Wiegand interface overview).

In this setup the intercom behaves like a card reader. Each suite gets a card number that matches its suite number (suite 1003 → card 1003). In the ACS, that card belongs to a user such as "Intercom – Suite 1003", with an access level for the front door plus floor 10.

• Why it works well: both logs show which unit let the visitor in. When a tenant moves out, the "Suite 1003" identity stays valid for the next tenant, so there's nothing to change in the ACS.
• Elevators come for free: because it's an ACS access level, the same event can enable the right floor.
• Watch for: the card numbers must not overlap with real credentials, so pick a facility code or number range for virtual cards.

Method 3: Cloud or API integration (DoorVi's approach)

What is it? Instead of wiring, the intercom platform calls the access control platform's API, and the ACS unlocks the door as if it were any other credential or remote unlock.

This is how DoorVi works with PDK (ProdataKey) and Brivo (DoorVi access-control integrations). With PDK, the visitor scans the DoorVi QR code or calls from the entrance, the resident answers on video in the DoorVi app and taps Unlock, and DoorVi triggers the linked PDK door. The visit is logged with the timestamp, the unit and who granted entry (DoorVi + PDK setup guide).

• No new wiring at the door: nothing controllable is exposed on the street side.
• The ACS stays in charge: door position, held-open and forced-door alarms, and schedules keep working as before.
• Where there's no cloud ACS: DoorVi can drive a network relay on the existing lock instead (for example a Waveshare ESP32 relay over MQTT; see the relay retrofit guide). In a building with an ACS, land that relay on an ACS input as in Method 1, not directly on the strike.

Elevator floor release: how it's usually done

What is floor lockout? In a typical elevator retrofit, relays are wired in line with each car's floor buttons. When the system is armed, those buttons are disabled until a valid credential enables them.

• Wire for failure: the relays are normally wired so that a power loss or controller fault enables all floors, rather than trapping people.
• Fire service always wins: access control must never interfere with firefighters' emergency recall (Phase I) or in-car operation. Coordinate the design with the elevator contractor and the local authority having jurisdiction (UpCodes: Phase I emergency recall, Code Red Consultants: fire alarm interface with elevator recall).
• How long to enable the floor: longer than the door's unlock time, because the visitor still has to walk to the elevator and wait for a car. A window of one to two minutes is a common starting point; set it from the real walking distance and car wait times.
• Newer elevators: many modern elevator controllers accept a direct integration with the ACS, or a destination-dispatch integration, in place of button relays. Ask the elevator vendor first.

User journey (a 120-unit mid-rise with PDK and elevator floor control)

Visitor

Before: the visitor calls from a wired panel, gets buzzed through the lobby, then stands in the elevator unable to press 10.

After: the visitor scans the QR code or calls from the entrance, sees the resident on video and gets let in, and floor 10 is enabled when they reach the car.

Resident

Before: the resident has to answer at an in-suite handset.

After: the call comes to their phone, even when they're away, and one tap unlocks the door.

Property manager

Before: the logs say "intercom opened door" and nothing more.

After: each release is logged with the unit and time in DoorVi and in the ACS, and residents are added per unit in the DoorVi dashboard.

Day 1: the integration is enabled and each unit is mapped. Week 1: fewer "who let them in?" questions. Month 1: the audit log is the answer to disputes.

Comparison

Where DoorVi fits best

• Buildings on PDK or Brivo that want video calling and per-unit logs without new cabling.
• Retrofits where running wire to every suite isn't realistic, because the call goes to the resident's phone.
• Sites that want nothing controllable at the entrance: the entry can be just a QR code, or a tablet inside the lobby.
• Doors with no ACS, where a network relay on the existing electric lock gives remote unlock.

When another solution makes more sense

• If the building has an on-prem ACS with no API and the elevator relies on Wiegand access levels, an intercom with a Wiegand module is the more direct route.
• If residents need in-suite monitors or handsets, a wired video intercom is the better fit.
• If there's no network available at the entrance, a POTS or analog phone-line entry system may be simpler.

FAQ

Does the access control system log which resident let the visitor in?

It does with Wiegand virtual cards or an API integration, because each unit has its own identity. With a plain dry contact, the ACS usually sees only a generic intercom release.

Won't the intercom's unlock timer fight the ACS unlock timer?

Not if the intercom sends only a short trigger and the ACS owns the unlock time. Problems start when both devices try to power the lock directly.

How long should an elevator floor stay enabled after a buzz-in?

Longer than the door, because the visitor has to walk there and wait for a car. Start around one to two minutes, then adjust for the building.

What happens to floor lockout in a power failure or fire alarm?

Floor relays are normally wired so that a failure enables all floors, and fire service recall must always override access control. Confirm the design with your elevator contractor.

Can a cloud intercom unlock doors without any wiring?

Yes, when the ACS has a cloud API, like PDK or Brivo with DoorVi. Where there's no ACS, a network relay on the existing lock is the fallback.

Is it safe to put the release relay at the entrance panel?

No. Keep relays and lock power inside the secured enclosure, so nobody can short the wires from outside.