Micro-reader Module
25 July 1996
VSL (24)
Pin 24 is for connecting the positive supply voltage (5 V) for the logic part.
CRDM (26)
Supplying pin 26 with a logic high signal causes the Micro-reader to run in a continuous charge-only
read mode (see Section 2.1.5 for more information).
When the CRDM pin is tied to logic low, the Micro-reader is in an idle state waiting for commands
via the serial interface or for a trigger signal (RDEN-) to start a single read out cycle. CRDM is a
high impedance input and must be tied to either VSL or GND via a suitable resistor (27 kOhm).
WLSC (27)
Pin 27 enables or disables wireless synchronization. To enable the wireless synchronization, pin 27
must be taken to VSL. When wireless synchronization is enabled, the Micro-reader will try to
synchronize its transmit signals with any other readers in range. To disable wireless synchronization
pin 27 must be taken to GND. Pin 27 is a high impedance input and must be tied to either VSL or
GND via a suitable resistor (27 kOhm).
Wireless synchronization can also be switched on/off by a corresponding command via the serial
interface. During execution of this command it has priority over the WLSC input.
OKT (29)
This output is set to logic high for approx. 60 ms if a valid transponder was read. It can be
connected to an LED externally to indicate the result of the read cycle.
STAT(30)
Pin 30 is set to logic low when the RF-transmitter is activated. Supplying an external LED with this
signal makes the status of the Micro-reader visible.
