Stand Alone Access Control Solutions From Securitron and Essex

March 3, 2010

The Securitron DK-26 is Securiton’s medium to high security keypad solution. The narrow keypad makes this system suitable for door frames with narrow frames.

The basic system is comprised of a controller which mounts inside the protected area, and the keypad which mounts on the outside of the protected area. The keypad is supplied with a 16-foot cable, which can be extended in the field up to the factory suggested 100 feet as required.

And additional keypad may be wired to the controller to add exit control to the system. (An expander module DK-XP adds 60 more users to the 59 user capacity of the basic product; as well the ability to print out activity reports to a serial printer.)

The unit requires 12-24 Volts AC or DC. The unit draws 160 ma @12 Volts or 190 ma @ 24 Volts.

Be sure to provide adequate power if you plan to operate the electric lock from the same power supply to avoid voltage drops which could impair performance. This is true whenever a power supply is used to power both the controller and the locking device.

If a single AC power source is going to be used, the DK-26 provides a DC Tap Output which supplies up to 2 amps of DC for the use with the locking device.

Whether you use a separate power supply for the locking device or not, for additional protection to the DK-26, a MOV is supplied with the DK-26 which attaches across the relay terminals. MOVs are Metal Oxide Varisters which suppress surges and arcing, thereby enhancing system performance and prolonging the life of the switch contacts.

The output relay is DPDT (2 Form “C”) and may be used with fail-safe, fail-secure locks or delayed egress locks such as Securitron’s IMXDa. The output relay contacts are rated at 5 Amps.

The cast stainless steel keypad is equipped with11 EPDM (ethylene propylene diene monomer) rubber keys, is weatherproof and vandal resistant and mounts on any surface including a narrow mullion.

Each button is an individual switch, so the DK-26 offers true 10-digit operation (keys are not paired).

The DK-26 is also available with a Wiegand output so that the PIN codes can be sent to external equipment. The DK 26W does not provide relay outputs or any other of the features of the DK-26, just a Weigand output.

The DK 26 offers what is referred to as a ‘Hard Code’ as well as fixed code programming.

Employ fixed programming in a situation where the end user is not likely to ever change the code, or at least that changes would be rare. Fixed programming can be used in lower security “traffic control” applications, as the longer the code remains unchanged, the greater the risk that an unauthorized person will be able to learn it.

The DK-26 makes it simple for you to program the unit in this “fixed” way. You will utilize a push button set, single code called the “Hard Code.” To delete the Hard code, press the “Hard Code” button on the CPU board, confirm that you are in hard program mode (slow yellow flash) and press the Bell key or wait 30 seconds.

Keypad Changeable Code Programming: In this application, two codes are programmed into the DK-26. The first, called the Program Code, acts as a password which allows changing the User code.

Thee User code is employed regularly to gain access. Knowledge of the Program code should be restricted to security management as its only use is to change the User code. With this method of operation, higher security is obtained because the end user can change the User code regularly or any time he feels it has been compromised.

This is the day to day procedure that should be taught to the end user.

Adding Multiple User Codes: The DK-26 has memory locations for up to 59 User codes. This allows separate codes for individuals or groups which is a benefit because when one code is changed (usually owing to a security worry), the people who use the other codes don’t have to learn a new code.

Test all the codes before you consider programming complete.

Note that you can individually erase any code (including the Program code) directly from the keypad

Use Of The Hard Code As A “Masterkey”: The primary use for the Hard code is to allow simple single code “fixed” operation. The Hard code can only be set or changed from the “Hard Code” button in the CPU board. It is deliberately kept separate from all programming functions.

Another use for it, however, is as a “masterkey” code since tis code can not be accidently erased by careless programming.

Subset Codes: Since the DK-26 accepts multiple codes of different lengths, it is possible that one code will be a subset of another.

The DK-26 avoids this problem by rejecting any code that is a subset of another code in memory. The DK-26 will also reject the attempt to program a duplicate code.

If your client is planning to allow individuals to choose their own codes without reference to a list, they may have to try alternate codes if the one they prefer is rejected as a subset.

Setting The Time Range And Toggle Mode: The DK-26 will release the lock it controls for 1 to 99 seconds (default time is 5 seconds)

The DK-26 will operate in toggle mode. In toggle mode operation, the relay will energize when a correct code is entered and de energize when a correct code is entered a second time.

When you have enabled toggle mode, activation of the REX input will successively energize and deenergize the lock control relay (just as if you entered the User code)

LED And Beeper Operation: As delivered, the DK-26 echoes key presses by a short beep and a short flash of the green LED.

The red LED comes on to show that the door has been released and also to confirm or reject programming commands (two flashes confirm; one rejects).

You can reverse the red/green LED logic so that the green light comes on when the red light did, and visa versa.

The beeper can also be re-programmed to sound when the door is released. Note that the beeper will continue to sound for its other functions. Beeping upon unlock is helpful if a silent type of electric lock such as an electromagnetic lock is being used.

When the person hears the beeper they know the door is unlocked.

Programmable Relay: The DK-26 CPU board includes a second 5 Amp, SPDT relay which may be programmed for different functions

Doorbell Function: By default the programmable relay will operate when the Bell key is pressed so persons outside the controlled door can request entry.

Duress Function: The duress function used for high security applications allows a person being threatened to release the door but simultaneously create a silent alarm which would be employed to summon assistance. To make this work, obviously the threatened authorized person has to enter something different than a standard User code. For this application the Hard Code is designated as a duress code. When a user code is entered, the door will open but when the Hard code is entered, the door will open and the programmable relay will switch. Connect the programmable relay contacts to a remote alarm or alarm panel, etc.

Anti-Tamper Alarm Function: Pressing 16 wrong digits will put the DK-26 into alarm. The keypad’s beeper and green LED will operate for 30 seconds during which time the keypad will accept no input. The programmable relay to operate during the alarm period.

Door Prop Alarm Function: This function activates the programmable relay to produce an alarm signal any time the door is left open too long after a valid entry or egress.

For this function a door position sensor must be installed on the subject door and connected to the DK26 cpu.

If the door is opened and recloses before the time expires, it will resecure immediately providing anti-tailgating.

If the door remains open for a longer period of time than is set on the timer, the programmable relay will switch and will remain energized until the door closes or the keypad is used again.

Note that if you are using the programmable relay for another function you can still enable this anti-tailgating but no alarm signal will be available.

Night Light Function: When this function is selected, the act of touching any key will operate the programmable relay for five seconds to turn on a lamp or video camera.

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Essex SKE Series

A good access control solution for single-door systems is the Essex SKE Series. These keypads come in 3 X 4 button matrix, which is the telephone-style single gang format, or the 2 X 6 narrow stile version, good for storefronts or door frames where the slim shape is more desirable. Both versions share just about all the same features except illumination.

The SKE models are described as self-contained access control keypads because they contain several operating features which allow you to provide a lot of extra features to your installation at a reasonable price point.

The keypads are Piezo, which means they are vandal resistant, weatherproof and will last since there are no moving parts. This ensures solid performance in any environment (heat, rain, snow, ice -up to 3/8”, -40°C to +70°C). A choice of architectural finishes is available.

The SKE has a 2A relay on board which is ample to operate most electric locking devices. It can be configured for 5 Volts DC or 12-24VDC. A linear or switching power supply may be used.

The SKE-26 is backed by a limited lifetime warranty.

The SKE is programmed from the keypad and will allow up to 502 users, with PINs from 3 to 8 digits. I recommend an 8-digit master programming code and 4-digit user codes.

Since the default Master Programming Code is by default 1-2-3, it is almost inevitable that you will wish to change this to a more secure number.

You will most likely want to create at least one user code. There are a number of parameters to consider when creating a user code.

Three outputs are available. The main output is the Form “C” (SPDT) (Com; Normally-Open; Normally-Closed) Dry contact which activates for a programmable length of time when a valid code is entered into the keypad.

The other two outputs (referred to as Output A and Output B) are referred to as open collector outputs rated a 250mA which are typically connected to relays.

So the SKE can be used to control as many as three doors, or three devices, or a door and another device, etc. Most projects will be comprised of a keypad and a door lock, but having the additional capabilities is a lifesaver where custom controlling is required. For example, it can also be used to control a garage door or electric gate. Two 1/4A grounding outputs are available which can drive a relay (separate relays required) to open a second door, trigger a CCTV or doorbell or control an auxiliary device.

Having those additional outputs can also give the technician a second chance. On a recent emergency service call, we replaced an old worn out keypad on the employee entrance to a department store which had failed on Friday afternoon, with no other entrance available to the employees other than the main doors which were inside the shopping mall.

My helper inadvertently miswired the main relay output of the new SKE 34S we were providing. We didn’t have another SKE 34 unit in stock, so I reprogrammed the unit so the code would activate one of the spare outputs, and added an inexpensive slave relay to save the day.

Two lessons learned: the SKE 34 has workarounds and keep a spare SKE 34 on hand.

An external connection is provided for a DPS (door position sensor) which may be the most useful enhancement which can be made to the basic access control.

When the DPS is used, the relay which controls the door lock will reset immediately after an access or REX is completed, rather than allow the door relay to remain energized for the number of seconds it is programmed to energize. This helps deter piggy-backing through the controlled door. Additionally, if a sounder is connected, the SKE will cause an alert if the controlled door is allowed to remain open too long (propped), or opened without a valid code or REX trigger first (forced).

Another input on the SKE allows the connection of a timer or switch. The SKE allows users to be entered as normal users or 24-hour users. When the Time clock feature is implemented, users enrolled as 24 hour users are unaffected, but normal users will not be able to enter if the time clock input is activated. This is used for premises where one group of employees would only require entry during normal hours, while management users might require unlimited access.

Another handy idea is the latching or toggle mode. The main relay is programmed to actuate for a certain number of seconds when a valid code is entered into the keypad. However for many applications, it is desirable for the door to remain unlocked for extended periods (for example for normal business hours). By making a user code a toggle or latching code, an individual who arrives at the premises in the morning enters a code and the latch command and the door remains unlocked until that user or another user who has been so empowered enters the code and the unlatch command, relocking the door again. All other users still enter their codes to achieve momentary access through the door.

For additional Locksmith Ledger articles on Essex products, visit

For additional Locksmith Ledger articles on Essex products, visit Web Site: www.