MagTek MINIWEDGE SWIPE READER - Manual (Page 17)

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SECTION 3. OPERATION
After the MiniWedge Reader is properly installed, power up the PC as usual. The LED on the
Reader remains off. The Reader determines the type of PC it is attached to by checking the
commands the PC sends to the keyboard when powering up. The LED then illuminates a green
color. The unit is then ready to read a card and receive commands from the PC. If the CRC (Cyclic
Redundancy Check) of the code is incorrect or the internal RAM is bad, the LED will be red until
power is removed. The keyboard will not operate. If the CRC of the parameter table is incorrect,
the LED will slowly flash red and green. The Reader will be disabled, but the keyboard will
operate.
Passing a card through the Reader causes the green LED to extinguish. The data read from the card
will be transmitted to the computer and appear on the display. The LED will reilluminate green
after all track data has been sent. All alpha characters will be sent in upper case if the option is
enabled.
When used with the MagTek Windows Drivers, the green LED will only illuminate when the
application program has enabled a read operation. This feature prevents card data from being sent
to an application that is not expecting it.
COMMAND CODES FROM THE PC TO THE READER
With a Reader attached to the PC, multiple devices can communicate with the PC. All communication
goes through the keyboard port. The Reader is directly connected to the keyboard port and the keyboard
or other device is connected to the Reader. When the PC receives the data from the keyboard port, it
cannot tell if the data has come from the keyboard or the Reader. Application software should be written
to read the information from the keyboard buffer to access the data. When the PC is first powered up, all
devices will be active.
The MiniWedge defaults to keyboard scan set 2 but will be switched by the BIOS to scan set 1 on some
models. The commands written to the Reader should be written to I/0 address Hex 60 for PS/2 Model 50
and AT computers. Commands should be written to Hex 68 for PS/2 Model 30 and PS/2 Model 25
computers. If the MagTek MTD Windows Driver (P/N 30037385) is being used, it will handle all
communication with the Reader.
The communication between the Reader and the PC is always active, and the Reader always responds to
the commands listed below, except when the card reading is in progress.
MESSAGE FORMAT
Characters used in the message format are as follows:
Characters Hex Value Description
<stx> 02 Start of Text
<etx> 03 End of Text
<cr> 0D Carriage Return