ib technology

3

The MicroRWD MF LP is a proximity system and a Read/Write range of up to 10cm can be

achieved under ideal conditions using the appropriate antenna. For evaluation purposes the

RWD is available on a base board with PCB antenna, LEDs, power-regulation, 9-pin RS232

and optional USB interfaces. When power is first applied to the board the red and green LEDs

flash once to indicate successful power-up (both LEDs stay on if initialisation fails). The

RWD can also check for antenna faults and internal error conditions, these problems are

indicated by the red LED or both LEDs flashing continuously until the fault has been

rectified.

The RWD will normally have the red LED lit until a valid card is brought into the RF field. If

the tag is accepted as valid then the green LED is turned ON (and red LED OFF). If the

auxiliary output features are enabled then the UID (serial number) is acquired, or block data is

internally read and transmitted as serial data or Wiegand protocol data on OP0/OP1 pins.

If the Beep delay is set then the “BEEP” output (pin 4) is pulsed ON/OFF. With auxiliary

output features turned OFF, the RWD responds to host commands on the TTL serial interface

at 9600 baud, 8 bits, 1 stop, no parity, as usual.

Note: Some ISO14443A compliant cards have a SINGLE (4 byte) UID and others have a

DOUBLE (7 byte) UID. These serial numbers are acquired as part of the initial

anticollision/select procedure when a card is brought into the field. This UID information can

be reported using the CARD UID command. For Mifare Classic 1k and 4k cards the SINGLE

UID is acquired and can be reported BUT subsequent block read/write operations will not

function if the Security KEY is incorrect for the particular sector and the authentication fails.

For many applications where only the UID (serial number) is required, the Security KEY

information is therefore NOT required.

MicroRWD MF modes of operation

The Micro RWD has two basic modes of operation:-

Remote mode (connected to a host computer or microcontroller) and Standalone mode.

1) Remote mode involves connecting to a host serial interface. This is where the stored

list of authorised identity codes (serial numbers) can be empty, effectively authorising

any Mifare card for subsequent read/write operations (depending on correct Security

Key. A simple serial protocol allows a host system to communicate with the Micro

RWD in order to program new authorised identity codes, change parameters, load

Security Keys and perform Read/Write operations to the card itself.

Antenna

Antenna

Micro RWD

Chip Module

Micro RWD

Chip Module

Host System

RS232

Serial

comms

Standalone mode with

Internal EEPROM holding

authorised Mifare serial

numbers for acceptance