Access Control: Query the Access Control Expert

Wires and Networks

Q: Do I run wires for all types of networks in the same way?

A: No. Some use a bus or backbone layout, others connect to each other, and others all connect to a central point. Still others mix portions of each type to form a network.

Choosing Factors

Q: How do I choose the type of network to use?

A: Your choice may be made for you when you select the type of access control system to use. But some systems will allow you a few options. When you select or evaluate a network, you should look at a few factors, including: how easy the system will be to manage, maintain and update; how easy is it for the users to operate; how does it impact the speed at which data is sent; how easy is it to add to the network; how does it handle faults; and, finally, how secure is the network from tampering.

Dial Direct
The Simplex 1000 Series mechanical pushbutton lock from Kaba access control is now available with the popular lockout feature directly from the factory. Previously, the feature required ordering an add-on kit. Lockout allows users to prevent combination entry by activating the lockout feature from the inside of the door. When lockout mode is active, entry is only possible via the lock's key override. Lockout is available on all 1021 and 1041 key override models by simply adding the letters LO to existing part numbers. For more information, call 800-849-8324

Compatibility is Prime
Q: What should I consider when choosing a topology?
A: Compatibility with your equipment is the prime consideration. When you have a choice between topologies there are a few considerations. Cost of connectors and equipment can vary; hubs, concentrators or routers may be required to process the signals and others require no additional equipment. A bus or backbone network will use less wire than one which requires a dedicated run to a central point from each device. Consider what is required to add additional devices. Also examine the cost and availability of the type of cable required for your system.

Not all systems are compatible with standard local area networks. While many systems are designed to connect to standard networks or the Internet others use proprietary formats to communicate.

Missing Lynx Found
ASSA ABLOY says it has found the missing electromechanical hardware link sought by installers since the advent of the electric lock. Dubbed ElectroLynx by company engineers, the new advancement is a wiring system with simple plug-in connectors that allow electromechanical hardware to be installed in seconds. The discovery will simplify hardware installations and make electromechanical locking solutions practical for any opening.

The ElectroLynx wiring system for doors and hardware is offered by CURRIES, McKINNEY and SARGENT and is compatible with electromechanical products from HES and SECURITRON. Each component of the ElectroLynx system the frame, hinge, door and locking hardware comes pre-wired with plug-in connectors that snap together to create a fully wired electrical opening. The plugs and wiring are concealed within each of the components to preserve the aesthetics of the opening and facilitate any future hardware changes.

The emergence of ElectroLynx represents a move toward universally wired opening components. The system will be offered as a feature on doors, frames and hardware produced by ASSA ABLOY Group companies.

The plug-in system provides flexibility for customers who may want to upgrade a mechanical opening with electromechanical hardware at a later date. Using the ElectroLynx system, an opening can be pre-wired from the frame to the door. The final plug-in link is concealed safely within the door, allowing the opening to be ungraded by simply plugging the electromechanical locking hardware into the hidden connector. The alternative is to tear apart the walls, frames and doors to run wiring not easy, not pretty and not cheap.

Get on the Bus
Q: What is the bus or backbone topology?

A: A linear bus topology is a system where all devices connect to a single main cable or backbone. A terminator is required at cable end to absorb the signal and prevent it from reflecting back across the bus. Signals are broadcast to all stations. Each device checks the address on the signal as it passes along the bus. If the signal's address matches that of the device, the device processes the signal. If the address doesn't match, the device just passes the signal down the bus. Only one device can talk' on a network at a time. Procedures are put in place to handle the collisions that occur from multiple signals. Devices in the bus topology are passive and simply listen' for a signal; they do not boost or amplify the signal.

Bus topologies can use twisted pair, coaxial or fiber optic cable and are easy to connect and require less cable length than a star topology. The entire network shuts down if there is a break in the main cable and the break can be difficult to identify. Required terminators can add labor and cost.

Achieve Precise Door Status
Dortronics Systems, Inc. offers an enhanced version of its versatile 7600 Annunciator Monitoring and Control Series. The modular system, expandable in four zone increments, can be configured to provide precise monitoring and control of over 100 doors/zones. The 7600 Annunciators provide greater capacity for large scale and complex access control applications.

The 7600 Annunciator Series panels are available for console or rack mounted use and can be hardwired or multiplexed. The units feature tri-state LEDs for each zone to visually indicate when a door is: closed and locked; closed and unlocked; opened with authorization; forced or held open; unsecured; and when an alarm has been sounded.

Doors can be remotely unlocked to allow momentary access or extended free access using the 7600 Annunciator Series panels. The panels are compatible with most NFPA compliant delayed egress systems. When used with Dortronics 101 Delayed Egress System, the status of each door is displayed on the unit and unauthorized exit attempts are reported as alarms. This device can also be used with the 7200-PT series Door Prop Alarms to provide feedback to security personnel when a door has been left unsecured. The 7600 Annunciator Series panels also monitor authorized ingress and egress by way of independent access control system or by manual station control hardware such as a key or keypad. For more information, visit

Star Quality
Q: How does a star topology compare?

A: All of the devices in a star topology are directly connected with twisted pair, coaxial or fiber optic cable to a central unit called a hub, concentrator or router. Data passes through the central unit that manages and controls all functions of the network and acts as a repeater for the data flow.

Star Topology systems are easy to install and wire. The network is not disrupted when individual faults occur or devices are connected or removed. The system requires more cable length than a linear topology and attached device are impacted if a related hub, router or concentrator fails. Cost of concentrators adds to system cost. The star topology is probably the most common form of network topology currently in use.

Flexible, Contactless Readers
Indala Corporation offers a series of MIFARE sector readers, which includes two models (wall switch and mullion-mount), four bezel styles, and several popular colors (black, white, beige, blue, and gray). The new readers are compatible with any MIFARE application and data format, which increases their flexibility. With their clip-on bezel design, the readers are literally a snap to install. As with all Indala products, the new MIFARE series is supported by Indala's customer care, fast shipping, and a Lifetime Warranty.

One of the great things about the Indala MIFARE reader is its flexibility. You can read the card serial number or, for higher security, any sector on the card you choose, states Marc Freundlich, Indala president. You can choose what keys/password protect the data inside. And, you can select from any of the great Indala reader cover designs since they are all interchangeable.

Indala also launches its FlexPass Heavy-Duty PinProx Keypad, which combines both a proximity reader and keypad in one small package. Designed to mount on a wall box or a flat surface, the fully-potted, metal keypad is weather and vandal-resistant. Constructed of PC/ABS Copolymer material, the Heavy-Duty PinProx Keypad operates from 4-16V, and is available in beige and black. The reader can be field programmed using the FlexPass ProxSmith Programmer as well as configured to output data in either Wiegand or magnetic stripe formats.

All Identification Types
Now available from Keri Systems is the BioPointe Fingerprint Reader with Wiegand output. For use on the PXL-500W Tiger Controller or any other manufacturer's Wiegand-compatible controller, each standard unit can store 720 user templates in memory while the optional Extended Memory units can store 4400 templates.

With its integrated keypad, BioPointe combines into a single unit many of the functions that require multiple products from other manufacturers. Individual users can be assigned to require PIN + fingerprint, fingerprint-only, or keypad-only. For those customers who prefer the optional embedded proximity reader to preload the fingerprint template, the same functions apply such that selected users can be assigned card-only status. BioPointe readers with embedded proximity are compatible with both Pyramid Series and HID cards/tags.

When multiple readers are employed in a system, they can be connected via an RS-485 network so that fingerprint templates can be shared from the enrollment reader to the other readers on the system via Keri's BioPointe Central software, which also provides management and reporting capabilities. When used with the optional KES-12 Hamster Enrollment Station, enrollment parameters can be optimized and enrolled users can be uploaded directly to the network. For more information, visit

A Token Ring
Q: What about token ring, how does that compare?

A: All the devices in a ring topology network are serially connected to one another in a closed circle of twisted pair or fiber-optic cable, so that each device is connected directly to two other devices, one on either side of it. There are no terminated ends to the cable. There may or may not be a fileserver.

Under the ring concept, a message is transferred clockwise sequentially via a token from one device to the next. When a device wants to transmit, it grabs the token, attaches data and an address to it, and then sends it around the ring. The token travels along the ring until it reaches the destination address. The receiving device acknowledges receipt with a return message to the sender. The sender then releases the token for use by another device. Each device on the ring has equal access but only one device can talk at a time. Ring topology is active because each device repeats or boosts the signal before passing it on to the next device.

Because the signal is regenerated by each node, the ring topology is expandable and adding devices has minimal impact on performance. All stations have equal access to the network. In a single ring topology, if one of the devices on the ring fails, than the ring is broken and cannot work.

A dual ring or counter-rotating ring consists of two rings transmitting in opposite directions. The intent is to provide fault tolerance in the form of redundancy in the event of a cable failure. If one ring goes, the data can flow across to the other path, thereby preserving the ring.

Residential Telephone Entry System
Channel Vision introduces the TE110, a reliable and cost-effective telephone entry system. The TE100 allows for communication between the front door and any phone line in the house. When a visitor presses the doorbell at the front door, the phones in the house will ring with a distinctive tone.

The TE110 also offers the ability to control a door strike with the use of an optional relay module (TE110DS) that is sold separately. The TE110 is composed of a printed circuit board (PCB) mounted in a 12x71/2 enclosure attached by a metal mounting bracket. The PCB unit can be purchased separately. Also available is the option to create a basic door entry system using the IU-series front door intercom included in the TE110BK or TE110WT kits.

For more information, visit

Branching Out
Q: What is a tree topology and how is it used?

A: A tree topology combines characteristics of linear bus and star topologies. It consists of devices arranged as a tree in groups of star-configured devices connected to a linear bus backbone cable. It is a common method used to expand local area networks.

The point-to-point wiring of individual segments makes it easy to expand a tree topology network. The overall length of each segment is limited by the type of cabling used. If the backbone line breaks, the entire segment goes down.

Brad Shipp is a former Executive Director and Training Director for the NBFAA where he authored several NTS courses, including the Access Control Certification course. His involvement in the access control industry dates back to 1974 and in 1986 he became an instructor for the NBFAA National Training School. Shipp has served on several law enforcement, regulatory and industry association boards and has been honored for his service by the False Alarm Reduction Association and the International Association of Security and Investigative Regulators. Send in your questions on access control to