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6. USE OF THE PROGRAMMABLE RELAY
The DK-26 CPU board includes a second relay whose 5 Amp, SPDT contacts are marked CX, NCX
and NOX (see Figure 2). This relay is employed for different functions which are selected by
commands sent to the CPU board while the unit is in program mode. In general, you need to
choose the function you want to make active for this relay (if any) and the following sections lay
out the choices.
6.1 DOORBELL FUNCTION
As delivered, the programmable relay will operate when the Bell key is pressed when the unit is
in "normal" operating mode (ready to accept a code).
programming operations but the relay will not operate during programming (including
initiating and exiting programming mode).
The purpose for this is to operate a real doorbell so that
unauthorized persons outside the controlled door can request
entry.
Most commercial doorbells are furnished with their own
power supply, so typical wiring is as shown in the drawing to the
right.
Note that if you don't plan to use this function, a blank
rectangular label is supplied which can be used to cover the
"BELL" legend on the keypad face.
person on the outside of the door.
6.2 DURESS FUNCTION
The duress function is used for high security applications. It 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.
The DK-26 handles this requirement by establishing the Hard code as a duress code. You need
to do several things however to implement this.
Ordinary operation must be via one or more User codes (see Section 4.2 for
programming)
Program the Hard code as your duress code (see Section 4.1).
Put the unit in program mode , and enter 7-5. You will see the two flash confirmation.
Exit program mode by pressing the Bell key or waiting 30 seconds.
Now, when you enter a user code, the door will open but when you enter the Hard code, the
door will open and the programmable relay will switch. The door will remain open for the
amount of time programmed but the programmable relay will stay switched (it latches)
until the hard code is entered a second time to reset it.
contacts (CX, NOX and NCX) to report the releasing of the door under duress. This can be done
by interfacing with an alarm panel or dialer. Note that a duress code is rarely used. To make
the code easier to remember, you can select a Hard code that is close to the User code (if only
one User code is being employed) or you can select a short hard code.
selection of this option means you give up the opportunity to implement a doorbell or other use
of the programmable relay.
6.3 ANTI-TAMPER ALARM FUNCTION
A person attempting to guess the code and 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. For high security applications, particularly when a lot of User codes
are active, you can assign the programmable relay to operate during the alarm period. Put the
unit into program mode and enter 7-6. You will see the two flash confirmation. Then, exit
program mode. You have now the means to report attempts to guess a valid code. This can be
done by interfacing with an alarm panel or dialer. Note finally that selection of this option means
you give up the opportunity to implement a doorbell or other use of the programmable relay.
The Bell key is used a great deal in
This avoids misleading a
Page 13
CX NOX
DOORBELL
POWER
SUPPLY
Use the programmable relay
Note finally that
PN# 500-16900
Rev. D, 12/11
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