For example, the integrated system can be programmed so that the identity cards used for access control can also arm and disarm the alarm system. This eliminates the need for employees to be assigned and to remember keypad codes – which, in turn, can eliminate the false alarms that occur when employees cannot remember their codes.

By adding video surveillance to an integrated alarm and access control system, functionality can be enhanced even further. An integrated system might signal the video surveillance system to reposition a camera when someone trips a door contact attached to the alarm system and to flag the recorded output. Alternatively, the system could be programmed to achieve the same result when certain employees use the card reader to open the door.

In the March and April issues of SDM, we discussed the benefits of integrating video surveillance, access control and alarm systems. In this article, we look at the connectivity and installation issues involved with integrated systems, which can be particularly complex when an alarm control is part of the system.

Interconnection methods

Systems integrators have three basic options for integrating alarm and access control systems.

One option is to attach alarm sensors directly to an access control system without using an alarm control panel. This can save money and simplify installation, but the programming options for the sensors will be limited. For example, it may not be possible to program the sensor for delay or panic. Another disadvantage is that if the access control system fails, the alarm system also fails.

Another option, available with some alarm systems, is to attach card reader/ door controllers or other access control devices, such as biometric sensors, directly to the alarm control panel. Typically such alarm controls accept a maximum of 15 or 16 access control devices, which manufacturers claim is sufficient for the vast majority of installations. And some manufacturers enable the access control devices to function in what is commonly called “degraded” mode if the alarm panel should fail. In degraded mode, the card readers or other access control devices do not look to the control panel for direction, but instead rely on information programmed into the door controller or into an access control panel to which the devices are connected. (Because this equipment has less memory than the central controller, operation may be less sophisticated than in normal mode. For example, in degraded mode, a card reader might accept any card holder in the system or any card programmed with the site code.)

A big advantage of using an alarm control with access control capability built in is that all devices are tightly integrated via software, enabling sophisticated functionality such as the ability to arm the alarm system with a passcard. One disadvantage of using an alarm system for access control is that the alarm system may rely on keypad programming, which can sometimes be a cumbersome way of entering the additional data required for an access control system. But some systems support a more intuitive graphic keypad. Alternatively, installers may be able to minimize or eliminate keypad programming by using a personal computer or Web browser interface to program the system.

The third option for installers wishing to integrate alarm and access control systems is to connect an alarm panel with a separate access control system. In this configuration, the access control system provides centralized control for the entire system. If a software package is available from the access control manufacturer that has been written to work with a specific alarm control, the two systems can be tightly integrated, providing the same benefits as an access control-capable alarm system – and more.

“On the programming and software level, it gives you a lot more,” says Joseph Riotto, president of Advanced Video Surveillance Inc., Fairfield, N.J. “The biggest feature is that reports are readily available through the access control system that include information about the alarm system.” Adds Riotto, “We’ve seen more and more specifications coming out requiring integration. Nobody knew what we were talking about before when we said, ‘integration.’”

Software integration

First, many access control systems today interconnect with a business customer’s local or wide area computer network, enabling authorized users to access the system from computer workstations also connected to that network. Some alarm panels also have computer networking capability. And when that exists, one installation option is to interconnect the access control and alarm systems via the local or wide area corporate computer network. The disadvantage of this approach is that it is more expensive than other connectivity options.

A less expensive alternative is to interconnect the alarm control panel and access control host computer via an RS-232 or other serial connection. The disadvantage is that there is a 50-foot limit on how far away the alarm panel can be placed from the host computer when using RS-232 to interconnect them. With an RS-485 serial connection, the distance requirement is less restrictive, allowing communications up to 4000 feet.

The third connectivity option is typically available only when using alarm and access control systems from a single vendor. This option involves interconnecting the access control host computer via RS-232 or other serial connection to a module attached to the alarm system’s communications or keypad bus. The advantage of this connectivity method is that it extends distance limitations substantially. However, it is sometimes not feasible to use an alarm and access control system from a single vendor, such as when adding an alarm system to a pre-existing access control system.

When using alarm and access control systems that are not integrated at the software level, connectivity is achieved by running wires from relay outputs on the alarm panel to inputs on a panel connected to the access control system. With this method, there is still a distance limitation, but it is less severe than for RS-232. The disadvantage of using relay outputs, however, is that installation is labor-intensive and the amount of information exchanged between the two systems is limited. All the access control system knows is that a certain alarm sensor is in a certain state.

That information is useful for a variety of functions, such as determining whether a door has been left open after someone uses his or her passcard to go through it. However, it cannot provide sophisticated functionality that requires exchanging more detailed information between the two systems, such as setting up a user in the access control system and having it flow through into the alarm system.

When interconnecting separate systems to create an integrated security system, it’s important to avoid creating single points of failure. “When you have independent systems, you want them to be able to run independently,” says Andy Farmer, director of sales for Tech Systems Inc., Duluth, Ga. To ensure this, installers would not want to attach alarm sensors directly to an access control system or attach card readers to an alarm control panel unless the access control devices can function in degraded mode.

Most customers understand the importance of avoiding a single point of failure, Farmer says, particularly now that the information technology department is involved in making decisions about security systems. “You don’t have to explain the dangers of a single point of failure because it’s important to the IT people as well,” says Farmer. “But you must show that your design avoids it.”

The access control system provides the intelligence for a security system that integrates intrusion protection and video surveillance.

Adding video

For an integrated system that includes an alarm, video surveillance and access control system, both the alarm system and the DVR would connect to the access control system using one of the methods described previously. Once again, the system will be more powerful if software is available for the access control system to integrate with the other systems.

In the event that software does not exist to integrate a particular DVR with a particular alarm control, it can sometimes be possible to use the two systems together by attaching both to an access control system for which software has been written to integrate both of the other systems.

Riotto sees access control vendors making software available to integrate with a wider and wider range of alarm and video surveillance systems. “Most of them are trying to achieve that,” says Riotto. “In another year, it will be commonplace.”

Sidebar
Five Alarm Panel Enhancement for Easier Systems Integration

Graphic keypads and Web browser interfaces can provide more intuitive programming for sophisticated alarm systems that include access control functionality.

Some alarm controls can easily connect to access control and video surveillance systems from the same manufacturer via the keypad or communication bus.

Some alarm panels can connect to a wide area or local area computer network, enabling them to easily exchange detailed information with access control and video surveillance systems.

Some alarm panels can communicate with the central station via a broadband connection such as a cable modem or DSL line, facilitating the transmission of data-intensive video images from the video surveillance system.