User's Manual

ADM Technical Description RFID-LSCAN
File: ADM UserMan.doc Page 8 of 12
Status: Rev1 Last Update: 9/21/2010 3:49:00 PM
Main physical characteristics
• Push-in push-out (double click) battery pack lock mechanism
• ON/OFF slide switch
• Reset button
2. MODES OF OPERATION
The ADM has two modes of operation: a) normal mode (power saving), b) continuous mode:
a) In normal mode, the unit is in sleep most of the time. It wakes-up regularly, based on a
Read Time Table (RTT). The RTT specifies the frequency of reads (e.g. every five
minutes) during a specific time interval (e.g. 8 hours). The RTT spans over 24 hours. One
can define up to eight time intervals in 24 hours; each interval can have a different read
frequency. In power saving mode, a read cycle can also be triggered by
vibration/shock/motion (if the vibration sensor is enabled). The power saving mode is
recommended for mailbox installation.
b) In continuous mode, the ADM is on all the time. The exciter generates continuously low
power LF field designed to catch test letters that are momentarily in the proximity of the
unit. This mode is intended for door slot installations.
One can combine power saving mode and continuous mode in the RTT. As an example, an ADM
can read tags continuously from 7:00AM to 4:00PM, every 10 minutes from 4:00PM to 9:00PM
and no reads from 9:00PM to 7:00AM next day.
3. FUNCTIONAL ARCHITECTURE
Essentially, the ADM is a battery powered, active RFID reader equipped with a GSM modem. It
performs the following main operations:
a) Generates LF excitation field
b) Receives UHF signal from tags
c) Transmits data and status information over SMS
d) Receives configuration command and parameter over SMS
3.1 LF Exciter
3.1.1 Operation
The exciter generates the low frequency (LF) field that is used to wake up tags. Once the tag
receives the LF signal, it responses on UHF. The excitation signal incorporates a (programmable)
unique address (LF field identifier). This LF identifier is received by the tag’s 125 kHz receiver and