Using Existing ID Badges for Access Control

Nov. 1, 2009
Using Existing Identification Badges To Control Access Into The Commissary

More and more companies are incorporating identification badges for their employees. The badges not only identify the employees, but also can be used to control access and provide time and attendance information. Some of them are even becoming “smart” enough to enable employees to buy coffee or a meal.

The basic employee identification first evolved from a photo and printed information to include mag stripes. For many years, the mag stripe along the back of credit and bank cards has been part of an employee’s badge. The stripe is being replaced by “Proximity” technology built into the badge. Proximity or “prox” are generic names for contactless integrated circuit devices having a read range of a few inches for the most common applications.
Proximity technology has an improved level of security over mag stripe and greater capability for adding encrypted information. In addition, a “prox” card eliminates the need to slide the badge into a card slot to be read. Instead, the badge can be placed near the reader as it emits an energy field. The ID card does not have to physically contact the reader to be read. This in itself offers a dramatically improved level of security as the reader can be shielded.
Proximity cards contain electronic circuitry, a temporary battery (capacitor) and an antenna (coil). The personal information is maintained in the electronics. To transfer the information, the proximity reader emits an energy field that is received by the antenna and charges the capacitor. When fully charged, the power flows through the circuitry, becomes Weigand protocol and is transmitted out the antenna.
The transmitted energy has become data, which is read by the proximity reader. The reader makes sure that the data is compatible in two basic areas - the site code and the User ID (card number). The site code is the facility identification and is part of every prox card or fob used at the facility. The User ID distinguishes each card (i.e. 100-499), much like a code. This number identifies the employee.
Access privileges can be set differently for some or all of the proximity cards. This is determined by the reader’s software, which includes the number of users, size of audit trail, time zones, sites, holiday scheduling, etc.
For this article, a standalone access control system was installed to control access for the front doors into a commissary. The commissary is a part of a non-descript building located away from the center of activity. The only customer access into the commissary is through double aluminum glass narrow stile swinging doors with no center mullion. Stops have been installed into the header above the doors.
For access into the commissary, each person must present his/her proximity equipped identification badge. This can limit the number of individual permitted into the commissary and limit the times of entry.
Because of this relatively unprotected location, the client did not want the proximity reader exposed on the exterior. The client also did not want the added expense and target of a protective exterior encasement. To solve this, they decided to install the SARGENT 4293 standalone proximity reader/keypad. The feature of the 4293 that gives this unit added versatility is the proximity antenna can be located up to ten feet away from the keypad/controller. The proximity antenna has been installed onto the right side of the double door entry. The antenna is small, black and non-descript. Unless you know its purpose, you could easily not see it. Should there be any vandalism or attempted forced entry, only the proximity antenna will be damaged.
In the opening left after removing the proximity antenna from the 4293, a cover plate or a “Press to Exit” button can be installed. For this installation, egress through the doors requires pressing the “Press to Exit” button or entering a User Code into the keypad.
The SARGENT 4293 is a fully integrated single-door access system. This standalone proximity reader/keypad does not require a separate controller in order to operate a lock mechanism. The 4293 supports all HID 125 KHz Wiegand formats (up to 40 bit). Up to 2,000 users can be programmed requiring single or dual credentials. The unit has the capability of up to 2,000-event audit trail.
The 4293 has a built-in 2 Amp relay for operating a lock mechanism. A separate (auxiliary) 2 Amp relay can be used for an alarm shunt or door status (switch not included). The 12VDC or 24 VDC SARGENT 4293 Proximity reader draws a small amount of current.
This Prox reader/keypad can be programmed at the keypad or can be managed using a personal computer operating SofLink. When networked, the 4293 has up to 20,000 individual user database capacity.
To individually secure each of the double aluminum glass narrow stile swinging doors, a decision was made to install the Securitron Shear, Self-Aligning Magnalock (SAM). The SAM is designed for traffic control applications. It provides magnetic holding force onto the top, edge or bottom of a swinging or sliding door.
For this application, the SAM2, a 600-pound holding force maglock was more than sufficient. The SAM2 are relatively small, 7.2” long by 1.15” wide by 1” tall. The sealed electronics are weatherproof and all ferrous metal surfaces are plated to resist corrosion. These UL Listed, Fail Safe electro-magnets have a current draw of 62mA @ 24 VDC. To ensure against residual magnetism keeping the door temporarily locked after power has been turned off, the SAM2 is equipped with an instant release circuit.
The SAM2 magnetic lock operates in conjunction with the spring loaded, shear strike assembly. The strike assembly contains two raised shear locator posts. The SAM2 is installed into the header using two special brackets. There is a recess in each of the brackets that accepts the strike assembly shear locator posts. The strike assemblies are installed into the openings along the top stile of the aluminum glass doors.
The SAM/SAM2 operate similar to maglocks with an important variation. When the SAM2-equipped swinging door is closed, energizing the magnet draws the shear strike assembly against the magnet face. Once the strike assembly contacts the magnet, the shear locator posts in the strike assembly enter into the cutout in the magnet brackets preventing any lateral movement. The door is secured from swinging for as long as the SAM2 is energized. When power is removed, the shear strike assembly retracts, disengaging the shear locator posts. The door can now swing open.
When the door is open and the SAM2 is energized, the door can close without having alignment of the shear strike assembly to the magnet. When powered, the shear locator posts keep the strike assembly far away from the magnet so it does not have holding force on the shear strike assembly. Once these locator posts enter the recesses, the strike assembly is drawn into contacting the magnet and locking the door.
Note: This shear locator post mechanism eliminates the need of sensors and timers to ensure the door is closed and at rest before the magnetic lock is energized.
The SAM2-24 Mini Shear Lock was installed into the aluminum header above the lock edge of each door. Both the magnet and the strike assembly were concealed, exhibiting no visible signs of a lock or locking mechanism.
To provide filtered and regulated (linear voltage) 24 VDC to the prox/keypad reader and the two SAMS, a Securitron BPS-12/24-1 field selectable, dual voltage power supply was installed into the equipment room at the rear of the commissary. The BPS-12/24-1 is a one Amp continuous current power supply which supports battery back-up. Output can run at 12 or 24 VDC to protect voltage sensitive electronics. A separate output provides the needed ten percent over voltage in order to charge the back-up batteries. Another feature of the BPS-12/24-1 is the AC failure monitoring function that can alert the access or alarm system of an AC power failure via SPDT dry contacts.
This installation was basically straight-forward. The ceiling joists ran in a favorable direction, from front to rear of the building providing an opening to run the wiring. The power supply was installed in the supply room roughly in line with the front doors.
There was almost sufficient crawl space for the wire run from the power supply to the front wall of the building. A plumbing bump-out for was used to run the wires from the crawl space down to install the SARGENT 4293 keypad onto the interior wall adjacent to the doors in order to provide egress. A hole was drilled through this section of the front wall to install the proximity reader.  The wires were run from the SAMS to the rear of the 4293 keypad.       

For more information, contact your local wholesaler or:
SARGENT Manufacturing Company, 100 SARGENT Drive, New Haven, CT 06511. Telephone: 800-727-5477. Web Site:
Securitron Magnalock Corp., 550 Vista Blvd. Sparks, NV 89434. Telephone: 775 355-5625. Web Site: