Timing Is Everything: Door Control & Security Timers

Timing plays an important role in door control and security. Timers, like everything else electronic, have undergone a major transmutation in a relatively short period of time.

Although many systems incorporate integral timing functions, there are also many applications where separate modules are necessary and there are specialized security products which incorporate timing features which enable the security installer to achieve the desired results.

The security installer must be able to identify:

• What needs to be accomplished with a particular site application.
• How to configure the products he installs to fully utilize the features designed into them.
• Know the modules and products available to the industry and identify the appropriate tool for each task.

When you are controlling a door with a card reader or receptionist button, it is typically required that the door remain unlocked long enough for pedestrians to transgress the opening. An individual approaches an opening and presents a credential to a reader or enters an access code into a keypad; the door unlocks and the person goes through the door. Or perhaps a visitor who uses an intercom to communicate with someone inside the protected area, or the visitor is visually identified from within the protected area and a remote release button unlocks the door.

The ability to remotely lock or unlock a door requires some type of electrically actuated device installed on the door assembly. Mechanical locks do not by themselves possess this functionality.

Many systems incorporate some form of an alarm located on the opening. This is so that the occupants (or security, or the police) can be made aware of a non-secure condition on the door. Non-normal or alarm conditions may also be remotely annunciation to a monitoring center. For example, the door may be ajar, propped open, forced or closed but not locked.

For retail environments, healthcare and child care, a forced door condition can occur when someone attempts to exit through a door not intended for casual egress, This matters if merchandise, patients or kids try to exit.

The system designer can provide an alarm or a variety of signals when one or all of these non-normal conditions exist at the door. Specialized timer circuits are required and sensors need to be incorporated to monitor conditions within the lock, and also the door's position.

Two main categories of this type of timer are door open timers and alarm shunt timers.

The door open timer is triggered by the valid request for access or by a remote door release button and the time the door remains unlocked is preset for let's say 5 seconds.

The alarm shunt timer is triggered by a valid request for access by a remote release button, or also by a valid request for egress. Once actuated this timer ‘shunts' the door position sensor and suppresses an alarm from occurring. The shunt may also be applied to a sensor from and external alarm system.

How long the lock is actually required to remain electrically actuated depends on the exact type of lock. Some bolt type locks will prevent a door from fully reclosing unless the bolt is retracted.

Varying site conditions will dictate door timing. For example, if the reader or keypad is necessarily located a distance from the controlled door, extra door unlock time may be required for individuals to reach the opening after they fulfill the access control requirement. Another factor may be elderly or handicapped individuals using the system who require additional time to achieve access.

The door position sensor is often used to signal the door unlock timer to cancel as soon as the access or egress has been achieved so the door relocks immediately.

Piggybacking and passback are two terms used for 'slipping through the door'.. In a piggyback someone follows a valid entry before the door relocks. In a passback, someone egresses while the door is still unlocked during a valid usage of the door.

Some access systems are designed to monitor credential and door usage. Depending on the system being used, this anti-passback feature may be applied to a single opening or multiple doors. Once a card is used to enter, it must be used to egress before it can be used to enter again. Or a credential may only be used to enter one time within a defined time period. Successive uses of credentials are typically employees trying to cheat the employer or allowing unauthorized individuals access. For example at a 24 hour gym. Freebies are Prohibited.

In multi tenant buildings, there might be a shared common door, and each tenant has an individual door to their space.  Often it is desirable to lock the common doors to prevent the public from entering the building before or after business hours, while allowing each tenant to control their individual doors. The main exterior door(s) are placed on a schedule to open and relock. Using the First Man In  feature, the door will remained locked until the first authorized person arrives and opens, then the door remains unlocked until the end of the day.

Some timers have time clocks built into them so they can control locking and unlocking based on the actual time of day. This is referred to as "real time" Most real time clocks like this have a single output so multiple schedules cannot be supported. One drawback is that if there is a power failure, they will no longer be operating, and will have to be reset once power is restored. Of course the alternative is an electronic timer with a battery backed up power supply. Whether there is line voltage or not, the timer is operating and still sending signals.

Allegion

Von Duprin 33/35A and 98/99 Series Exit Devices are put to the ultimate test every day in thousands of schools, hospitals and government buildings. These facilities with high abuse applications minimize installation time, maintenance costs, downtime and liability by investing in quality.

The 33/35A series and 98/99 series are unique because of the configurability and breadth of application coverage. Not only do these devices provide the widest range of electromechanical options on the market, there are also kits available to retrofit existing devices. These kits provide additional flexibility all while protecting your warranty and UL listing with genuine Von Duprin parts.

33A/35A devices are ideal for narrow stile doors. They fit door stiles as narrow as 1 3/4" (44mm).  98/99 devices are ideal for standard stile and solid doors.

33/35A and 98/99 Series exit devices are available in two external surface styles. The 33A and  99 Series devices feature a grooved  mechanism case, 35A and 98 Series devices feature a smooth mechanism case. The two styles are mechanically and dimensionally identical and provide a wide selection of appearance options.

Popular Options for 33/35A and 98/99 Series devices include Quiet Electric Latch Retraction, Wood Door Concealed Solutions, Accessible Devices and Security Dogging Indicators.

The Chexit delayed egress system meets requirements of NFPA 101 for special locking arrangement. New Chexit features which benefit the customer by making installation maintenance easier:

• PCB mounted on baseplate
• Removable keyswitch does not interfere with selecting options
• Basic maintenance does not require removal of end cap bracket
• Field replaceable RX switch. (No longer requires replacement)

Additional Chexit benefits for your customers include:

• Motor driven blocking actuator
• Low amperage power supply requirement

• Selectable nuisance delay 0,1,2,3 seconds
• Hi/Lo selectable audio output level
• Selectable power setting (armed or disarmed with alarm sound (conforms to California Code)
• Trim actuator/input for outside trim connection
• Selectable trim failsafe/failsecure setting
• Secure status relay output
• Devices to include XP98/99 and 33A/35A verticals

More Info: http://www.us.allegion.com

Altronix

The Altronix PT724A is an extremely versatile 24-hour, 365-day Event Timer designed to support a wide range of applications: Home and Building Automation, Security, Access Control, Lighting Control, etc.

The PT724A are equipped with an independently controlled form “C” relay contact that provides many latching and/or momentary operations during a program schedule of your choice. Events may be set for single or multiple operations on a daily and/or weekly schedule. This timer is so easy that management can sometimes operate it.

Features include:

• EE Prom memory protects against loss of programming due to power failure.
• Accurate crystal controlled clock.
• Momentary and/or Latching Events.
• 50 individually programmed daily/weekly events.
• Block programming capacity can accommodate a total of 350 events per week.
• 10 programmable Holiday dates.
• “First man in” option.
• Standard or Daylight Savings Time settings.
• Automatic compensation for Leap Year
• Integral battery charger
• Optional Lithium battery for clock

The Altronix PT2724 is similar to the PT 2724A except the PT2724 is equipped with two independently controlled form “C” relay contacts that can be independently controlled or controlled in tandem.

The 6062 Programmable Timer is suitable for many functions that require a timed operation e.g. access control Applications, Siren/Bell Cut Off Module, Dialer Delay, Guard Tour Supervisory Timer, etc.

More Info: www.altronix.com

Camden Door Controls

Camden's CX-247 seven-day time is an affordable, compact and easy to program electronic timer that is designed for use in a wide range of control applications. The unit supports up to 8 'on/off' scheduled times per day and is available in 12 or 24 Volt models.

It is ideal for automatic enable/disable of door activation devices, lighting control, energy management and other general control applications.

Features include:

•        8 daily or weekly schedules

•        Internal memory back-up

•        Easy to program/ setup

•        Extremely compact size

•        12V AC/DC and 24V AC/DC models

•        SPDT contacts rated 16 amps @ 30V DC

•        Dimensions: 2 3/8" x 2 3/8" x 1 1/4"

•        'H' models feature 'First Man In' function (for holiday/snow days)

More Info: www.camdendoorcontrols.com

Seco-Larm

Seco_Larm’s Model SA-027HQ  is a 365-day annual timer ith two relay outputs. Each relay can be programmed for 50 events, for a total of 100 individual programmable events. Events can be set weekly, daily, or hourly, over the course of an entire year.

Features include:

• Manual operation of relays without event programming.
• Block programming allows events to be repeated.
• First-person-in function interrupts the timer's normal operation.
• Event outputs can be programmed disable, ON, OFF, shunt, or momentary (1~99 seconds).
• Password-protected programming.
• Tandem mode allows both relays to operate simultaneously.
• EEPROM Memory for data protection in case of power failure.
• Built-in clock backup battery. and backup battery charger for external backup battery use.
• Alphanumeric backlit LCD display for easy programming.

More Info: www.seco-larm.com

Securitron

The Securitron IMXDa (Integrated Movement Exit Delay with Advanced Technology) timer helps prevent peril to persons/patients and property loss/theft for businesses. Applications include dementia wards, hospitals, dormitories, airports, child care facilities and retail or warehouse environments. Installation requires no alteration or replacement of existing fire-rated or non-fire-rated latching hardware. False triggering is eliminated by up to 1" of authorized door movement.

Features include:

• 1200 lbs. holding force Magnalock
• New shorter 12.5" overall length will fit most any door with a closer installed
• Automatic dual voltage - no field adjustment required
• New bracket-mounted design improves strength and installation time
• Microprocessor monitored BondSTAT magnetic bond sensor (MBS) and integrated door position switch (DPS) standard
• Reverse action plunger allows for adjustable alarm initiate gap from 1/8" [3.2mm] to 1" [25mm]
• Bright LEDs indicate unit status from the secure side of the door
• DIP switch selectable options

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Securitron also offers a number of timers, including the Model DPA, a multi-functional control timer that operates as a door prop alarm, and the Model DT-7 Prime Time Digital Timer, ssed to turn electric locks or other security systems on and off at programmed times.

More Info: www.securitron.com