Knogo North America Inc WDD User Manual
Knogo North America
8MHz Wrap Desk Deactivator
Installation Procedure
8MHz Wrap Desk Deactivator
Installation Procedure
1.0 System Description.
The 8MHz Wrap Desk Deactivator is an accessory normally used with the P and T series
RF detection systems. The P and T series detection systems provide the ability to detect
small parallel LC resonant circuit tags in a zone of up to 6 feet between the receiver and
transmiiter antenna. The system is normally installed at the exit doorway to the store. The
Wrap Desk is normally installed at the point of sale register and detects the same tags on
the merchandise at a much smaller range. Sales personnel can then be made aware of
concealed tags on merchandise that is being rung-up at the register. This prevents
embarrasing alarms on paying customers if they were to exit the store with tagged
merchandise. It also has the capability to deactivate small disposable tags. Deactivation is
acomplished by inducing enough voltage into the tag so as to exceed the breakdown
voltage of the tuning capacitor resulting in a short circuit that turns the tag off.
RF detection systems. The P and T series detection systems provide the ability to detect
small parallel LC resonant circuit tags in a zone of up to 6 feet between the receiver and
transmiiter antenna. The system is normally installed at the exit doorway to the store. The
Wrap Desk is normally installed at the point of sale register and detects the same tags on
the merchandise at a much smaller range. Sales personnel can then be made aware of
concealed tags on merchandise that is being rung-up at the register. This prevents
embarrasing alarms on paying customers if they were to exit the store with tagged
merchandise. It also has the capability to deactivate small disposable tags. Deactivation is
acomplished by inducing enough voltage into the tag so as to exceed the breakdown
voltage of the tuning capacitor resulting in a short circuit that turns the tag off.
The transmit signal from the system is a sequence of RF bursts between 7.5MHz, and
8.9MHz. This signal is amplified and low pass filtered before it is fed to the transceiver
antenna loop. During the transmit burst, if a tag is placed close to the antenna it will
absorb energy from the field. After each burst, there is a delay which allows the trasmitter
output to decay.
8.9MHz. This signal is amplified and low pass filtered before it is fed to the transceiver
antenna loop. During the transmit burst, if a tag is placed close to the antenna it will
absorb energy from the field. After each burst, there is a delay which allows the trasmitter
output to decay.
The receiver processes the remaining signal on the antenna which is the energy released
by the tag. The signal is detected and is fed to a sample and hold circuit. If the tag has the
correct signature, the alarm is sounded.
by the tag. The signal is detected and is fed to a sample and hold circuit. If the tag has the
correct signature, the alarm is sounded.