Intercoms For Access Control & Security

Feb. 1, 2009
Applications include vehicle entry gates and healthcare providers like managed care facilities.

Using intercoms in access control enhances the security of any system. One obvious reason is because intercoms involve a human in the process. An employee can carry on a conversation with the entrant, and often receive visual confirmation.

Hopefully those in control will exercise good judgment in how they control access into the premises. I use the word hopefully because at one time I installed apartment intercoms in New York City, and in multiple dwellings, this was unfortunately not always the case. Tenants did not always screen individuals they allowed in.

Today the public has matured, the technology has evolved and more people take their security seriously. Entry systems are more sophisticated, and facility management places a higher priority on keeping entry system functioning properly.

In suburban markets, the locksmith is far more likely to deal with single point or commercial building security. Intercom work can involve the integration of voice (telecom) and or video with door and gate control systems.

Vehicle Gate Intercoms present a special set of challenges, namely, wiring challenges, environmental conditions, and specific issues regarding gate and user interfacing.

Recently I was hired to provide an intercom system for the main entry gate into my client’s industrial site. This application was for what is referred to as a point-to-point system. This means that the gate would only communicate with the guard station. Sometimes multiple points of control are requested.

The gate was far from the main building and we didn’t want to have to trench through the paved parking lot. There was an existing cable trough to a junction point and another from the junction point to the main building where the guard desk was located. The main issue was distance. It would require about 1000 feet of wire to connect the two stations.

The Aiphone AP-1M can go 490 feet using #22 gauge cable, and 1200 feet using #18 gauge. wire.

The Vehicle gate was accessed by both passenger vehicles and big trucks. Some had credentials which would open the gate after hours. However some would not, such as deliveries, guests, employees who forgot their credentials, emergency services, etc.

Did I mention this was an outside vehicle gate? There was no protection from the elements and rarely any protection from wayward vehicles.
Inside the building, the guard is surrounded by video monitors, the access control workstation, telephones, intercoms, the fire alarm panel, and employees. The inside intercom station had to be loud enough and durable enough to withstand abuse.

We used an Aiphone AP-1M master station in conjunction with an Aiphone 8 Ohm hands-free horn. This system was selected because it had the power to run that length of cable, had plenty of volume and clarity within the building, allowed us to connect a ‘Call’ button out at the gate to notify the guard that there was someone out there requiring their attention, and was hands-free so there was no handset required by drivers.
Using the correct cable is imperative if you expect the Aiphone to operate correctly. We did, and the Aiphone has worked perfectly since deployment.

This client provided rehab and extended care to its clients. Weekends were particularly challenging because besides having to maintain their normal activities, the staff had to control a lobby door which remained locked at all times to prevent patients from wandering off and also to admit other staff, visitors and EMS workers.

A reliable video intercom was in order. The intercom station in the lobby was located adjacent to the controlled door. The intercom base unit was located at the primary nurse’s station. This particular nurse’s station was always staffed since the patients in this wing required a higher level of care than on other wings. Also being constantly staffed, this position was considered the after hours command post from which care meals and drugs were dispensed.

The Aiphone MK-1GD is used as the nurse base station, and an Aiphone MK-DV is used in the lobby.  This is a fixed-camera black and white video intercom which provides the cost-effective, reliable operation this facility requires.

Frequently nurses are out on the ward, so we added an IER-2 Chime Extension Speaker to the base unit so the nurses are sure to hear when a visitor presses the Call button. The IER-2 has its own volume control, so when the nurses are all near the intercom, they can turn the volume of the call button down, or when they are not close by they can turn the volume up.

The MK-1GD has and integral unlock button for controlling the locking mechanism at the door. In this application we are triggering an input on an access controller. If the intercom is going to control a locking device directly by switching voltage on and off, an optional slave relay is recommended. This spares the internal contacts on the Aiphone the wear and tear of the high current and surge associated with powering strike and maglocks, which would shorten the life of the unit, and also generate noise over the communications line.
For more information, contact Aiphone Corp., 1700 130th Ave. NE, Bellevue, WA 98005. Telephone: 425-455-0510 or 800-692-0200. Web Site:

Emergency communications is a priority for universities as well as other entities such as manufacturing complexes, commercial industrial parks, shopping malls, hospitals and mass transit. 

Responsibility for a student, employee, patient or customer’s well-being does not end at the door of the facility. Emergencies can be as mundane as a car which refuses to start or as critical as a medical crisis, or criminal act. The Security team needs to know there is a problem before they can take action, and emergency communications systems help to fulfill this need.

Talk-A-Phone Co.’s Wide-Area Emergency Broadcast System (WEBS®) is a family of mass notification devices that can be integrated into a comprehensive emergency communication system for a multitude of locations. WEBS units can be situated in a variety of mounts and locations, bringing security coverage to heretofore-neglected corners of a facility. Tone or voice messages can be delivered to specific units, regions, or to all units at once, allowing for flexible emergency response.

Analog and Native IP versions are available. WEBS models can also be made wireless with Model VOIP-RF, extending security’s footprint even further. The wide array of installation options makes WEBS a valuable security instrument at college and corporate campuses, mass transit locations, and parking facilities. WEBS installations can also be integrated with surveillance cameras and strobe lights for robust coverage. Tower, wall and pedestal mounts are available.

For more information, contact Talk-A-Phone Co., 5013 N. Kedzie Ave., Chicago, IL 60625. Telephone: 773-539-1100. Web Site:

Intercoms are essentially elements of the telecom system. Viking Electronics manufactures devices which combine intercoms, security and door control.

The Viking Electronics SRC-1 enables a standard touch-tone phone to securely operate a set of timed relay contacts to control a door strike or gate controller at a remote location.

The SRC-1 is fully user programmable and uses non-volatile memory. It eliminates the possibility of dialing the activation code through the entry phone using a hand held touch tone dialer.

The SRC-1 features a switchable 32V talk battery to allow use with any of Viking’s entry phones (E Series), door boxes (W Series) or hot-line/panel phones (K Series).

The SRC-1 is installed between the entry phone and the secure phone, and will reject touch tones from the entry phone and only operate the relay if the correct activation code (user programmable) is given from the secure phone. The SRC-1 also provides up to 32 keyless entry codes to operate the relay from the entry phone with 1 to 6 digits. This feature can be disabled in programming for increased security.
Locksmith Ledger interviewed Viking Electronics SRC-1 product manager James Catt about this product. Following are our questions and his answers.

Can you tell us about the SRC-1?
The SRC-1 is a new product for this year. It needs to be used with an entry phone (E-10A, E-30, E-60, K-1700-3, etc.) or doorbox (W-1000, W-2000A, W-3000) (sold separately) and adds remote touch tone control of a door strike to an existing or new installation.

What type of device is this dialer that can be used to trick telephone entry systems?
The handheld touchtone dialer is a product that is getting rarer to find, but can now be emulated by PDAs and cell phones. It is simply a device capable of producing DTMF tones through a speaker that is held up to the microphone of the entry phone.

What entry systems out there are vulnerable to this form of attack?
Any entry system that relies on touch tones to activate the door strike or gate controller that does not attempt to verify the direction of the detected tones. This allows either the caller or the operator to activate the device with the correct touch tones. The normal methods to prevent the caller from activating the door strike are either obfuscation by keeping the activation code secret, or not providing the caller with a keypad. However, the handheld dialer circumvents the no keypad protection method.

Am I correct to say that end-users could be issued up to 32 unique PINs, and they could use their cell phone to gain access?
You are correct in that the end-users could be issued up to 32 unique keyless entry codes, but the usual way to use a keyless entry code is to have an entry phone with a keypad (i.e. the K-1700-3 or K-1900-8) and for the tenants or employees to go off-hook with the entry phone and dial ‘#’+ their code on the keypad to activate the door strike. Thus a cell phone is not required for keyless entry.
For more information, contact Viking Electronics, 1531 Industrial St., Hudson, WI 54016. Telephone: 715-386-8666. Web Site: