One of the most expensive challenges awaiting organizations wishing to integrate their various alarm/access control systems is that there may be numerous different card types, with varying card bit formats. Some sites may use magnetic stripe cards, others may use Wiegand swipe cards, still others may use one brand or another of 125-kHz proximity cards, and some may use smart cards. Of course, where the card formats are the same, it is possible that the bit formats may still differ.

Therefore, one of the biggest challenges is for the organization to make a decision regarding what access control card technology to use. At the time of the writing of this book, the National Transportation Workers Identification Card (TWIC) provides a single uniform credential that is more difficult to counterfeit and misuse than many past cards. Several different card technologies are all present on a single TWIC card, including a biometric credential reference standard for the cardholder that is embedded in the smart card, magnetic stripe, and smart card touch or touchless technology. TWIC card concepts are a good choice to use to merge older card populations into a single new standard.

Interfacing Multiple Access Control Systems from Differing Manufacturers into a Single Comprehensive System

One of the normal challenges faced is that alarm/access control systems software and hardware are almost always completely incompatible from one manufacturer to the next. Integrating different brands and models of video and intercom systems is not nearly as complicated as integrating different brands of alarm/access control systems. Thus, if your client is one of the many whose various security systems involve numerous alarm/access control systems at various sites, one of the key decisions is to determine whether to immediately implement full and total integration of the alarm/access control system.

The obvious advantage to having a single alarm/access control platform is that it makes both alarm monitoring and access control management very easy. The disadvantage is that it may require substantial replacement of various alarm/access control systems with a single brand. There are other options, however.

One option for centralized alarm reporting for remote sites is to leave the access control management integration for later and integrate the alarm management portion first to achieve centralized monitoring. That is relatively easy.

Several options exist for achieving centralized monitoring.

Digital Video Recorder-Based Systems

The arguments for:

• Digital video recorder systems can be built from small systems to fairly large systems over time with minor incremental cost for each step.

• The organization has only to buy as many DVRs as it needs to add at a time.

• DVRs can be networked together (some better than others) into fairly large systems.

The arguments against:

• DVRs often become obsolete in a very short time, having been replaced by a newer recorder with more recording capacity and better features in less than two years.

• DVRs lock the client into a single brand of equipment because their operating formats are generally not compatible from brand to brand.

• Many DVRs only work with analog video cameras and cannot work with signals transmitted to a switch across a digital infrastructure.

• DVRs may become obsolete due to their inability to keep up with new recording capacity demands. What seemed like a lot of storage two years ago may seem totally inadequate today. The cost of updating the storage capacity for a digital video recorder may outweigh the benefits.

• Some digital video recorder manufacturers have produced a nonlinear progression of recorders such that the client may have to abandon all previous recorders in order to expand the system beyond a certain capacity. This obviates the benefit of the scaled approach to building a digital video system.

• DVRs have a finite life, and the entire unit may have to be replaced more often than the client would like.

Proprietary Hardware-Based Server-Type Configurations

The arguments for:

• Proprietary hardware-based server-type systems have most of the advantages of software-based systems but do not have some of their disadvantages.

• Specifically, hardware-based systems are very easy to install and configure. Because they are hardware based instead of software based, most system configurations are built into the hardware. Once it is connected, it boots up and works as planned.

• System installation and reliability over time are likely to be very high.

• The system may require far less expertise to install correctly.

• It is less likely that a computer-savvy guard would try to reconfigure the system to his or her own taste, possibly rendering the system inoperable in some capacity.

The arguments against:

• Hardware-based systems lock the client entirely into that manufacturer’s products. This may not be bad, if the products are available for installation from a variety of contractors, can be maintained by a variety of agencies, and have enough installation and maintenance options to make the product competitive over time. If not, what may look like a very good deal in the first installation may become quite costly as the client realizes that he or she has limited options for availability of the product. Many clients wish they had never made proprietary decisions.

• Hardware-based system functions are built into the hardware. They do what they do because of what they are physically. If a need develops for a function that was not realized when the system was purchased, it may not be possible to add it.

Software-Based Server-Type Configurations

The arguments for:

• Software-based server systems are the purest form of digital video technology: Almost all are composed of off-the-shelf network hardware with the functions operating entirely in software.

• Because they are based on standard computer switches, routers, servers, and workstations, software-based systems provide the ultimate in system configuration flexibility.

• The systems operate on conventional servers and workstations, so the client can have his or her choice and use the product that fits his or her own corporate culture, making the system easy for the information technology department to service.

• Many software-based systems are completely nonproprietary. That is, the client can use any digital video camera, and the software can be replaced without loss of stored data.

• Some software-based systems are far more flexible in their functions than their comparable hardware equivalents.

• Some software-based systems make integration to legacy analog and digital video systems much easier than their hardware counterparts.

The arguments against:

• Software-based systems are based on standard servers and computers, so they suffer from all of the flaws, vulnerabilities, and foibles that go with nondedicated systems, including some dangerous operating system vulnerabilities.

• Because they are based on conventional operating systems, the configuration of the operating system and data infrastructure requires higher skills in order to ensure a stable, secure system. A skilled (or even improperly inquisitive) guard can easily corrupt the configuration of an improperly configured operating system that serves as a platform for the digital video software system. To be fair, this can also be a factor in conventional alarm/access control systems and even hardware-based digital video systems, if the workstation operating system is not configured correctly.

• Software-based digital video systems require higher skill levels to commission properly.

Analog Switcher Interfacing

Interfacing a digital video system to an existing analog matrix video switcher can be either straightforward or an extreme challenge, depending on the digital video system to which it is to be connected. Some software-based systems are very well thought out with regard to this issue, whereas DVRs and some hardware systems are, at best, a mixed bag.

The objective of legacy matrix video switch integration is to make the matrix switches of various manufacturers at various locations all operate as though they belong to the family of the digital video software. This is actually not a difficult task because most analog matrix video switches provide a data interface format for their switches. By engineering a communications protocol based on the data interface format, the digital video software vendor can create a toolkit of interfaces for each brand. At least one software manufacturer has done this; more will follow.

Thus, it is important to ensure that the digital video product you specify can interface to a legacy analog video matrix switch if such exists within the enterprise for which you will be designing. Communications with older matrix switches should employ a method that facilitates Ethernet connections so that the interface can be made across wide geographic expanses.

Multiplexer Interfacing

Multiplexer interfacing is not as easy as it is for analog switches. It is possible for digital video manufacturers to write interfaces to control multiplexers, although this is not commonly done. The other way is to take the output from the multiplexer’s monitor output into a digital video switch codec input. This will allow the digital video system to display the output of the multiplexer as though it were itself a video camera. When this is done, it will also be necessary to control the multiplexer, which can be done through the multiplexer’s data control input. Most multiplexer manufacturers make accessory products that can allow the networking of their multiplexers under a single remote keyboard command. In this case, the digital video software will provide the commands to control the multiplexers.

One of the most common security intercom products is a two-wire intercom made by Aiphone™. This versatile intercom has been used extensively in very small to relatively large applications for many years, so it is likely to be encountered repeatedly throughout a security designer’s career.

The two-wire intercom incorporates talk, listen, call, and remote door-release functions onto a two-wire infrastructure. Although this is economical on cable, it presents challenges to convert to a digital infrastructure.

The two-wire intercom manufacturer makes an Ethernet converter for its intercom stations, as does at least one digital video software manufacturer. The product converts the intercom directly to an Ethernet signal, whereas other products convert the Aiphone signal to a standard four-wire intercom interface, suitable for use across a variety of other codecs. Either of these two approaches provides a reasonable migration path for this popular two-wire intercom.

Four-Wire Intercom Systems

There are a variety of so-called four-wire intercom systems. Some of them actually use more than four wires, although designers still lump them into the four-wire group. A four-wire intercom uses two wires for talk, two for listening. It may use separate cables for intercom call and remote door release, or it may include these functions on the original four wires. Several digital video and intercom manufacturers make four-wire-to-Ethernet converters, and most digital video codecs will accommodate a four-wire intercom directly.

Intercom Matrix Switches

Another type of intercom system designed to accommodate larger installations is the intercom matrix switch. This operates much like a PABX, but it is dedicated to intercom use only. Matrix switches are offered by a number of manufacturers, but their use is likely to decline with the advent of digital intercom switches. Like a PABX, there is a matrix switch, one or more intercom master stations, and a number of intercom field stations. On larger systems, there may be a number of intercom matrix switches all networked together via audio and control lines.

Some of these are very difficult to convert to digital systems, particularly older matrix switches. Newer switches often have a data interface protocol that will allow an outside unit (in this case, a codec) to act as the talk path, and the matrix switch can accept RS-232 commands and provide call requests via RS-232. In a few cases, a software API or XML interface may be possible.

Check with the manufacturer of the specific matrix switch to determine how they can adapt to a digital intercom system. Many of these companies offer digital intercom systems of their own, making this transition easier.

In the first edition of this book I said to expect to see a new architecture for alarm/access control systems begin to emerge in the near future. Unlike existing alarm/access control system architectures that wire a number of field devices from doors and alarms back to a closet where there is an alarm/access control panel, expect to see a new architecture in which each door may be served by its own individual controller, locally at the door. This has taken place. This allows for the connection of one or two card readers, door position switch, request-to-exit device, low-power door lock, one or two digital cameras, and a digital intercom (on Ethernet connections) all on the microcontroller (Fig. 13.2).