HITAG S -- 3rd generation HITAG?
family
Modulation Read/Write Device to Transponder: 100 % ASK and Binary Pulse
Length Coding
Modulation Transponder to Read/Write Device: Strong ASK modulation with
Anticollision, Manchester and Biphase Coding
Basic System Configuration
The following block diagram shows in principle the HITAG system
configuration
A control and data processing unit controls the modulation of the carrier
signal and processes data coming back from the demodulator circuit.
Absorption modulation is used, when sending data to the read/write
device.
To force the absorption of the magnetic field, the transponder in
principle turns on/off an internal resistor.
With the resistor turned on, the physical state is named Modulator ON
(loaded) otherwise Modulator OFF (unloaded.)
Two different codes are used for the transmission of data to the read/write
device:
The first bit of the transmitted data always starts with the Modulator ON
(loaded) state.