Desktop Reader Manual V2.1
26/02/2007
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depending on the Track but on the data carried by the Track. The rule to determine which encoding to
be used (BCD or ALPHA) with the Tracks is:
•If all the ASCII characters of the Track are included in the BCD symbol set
(0123456789:;<=>?) it uses the BCD encoding (4 bits + parity).
•Otherwise it uses the ALPHA encoding (6 bits + parity). And if the data finishes with the End
Sentinel (?) the Reader calculates and adds the LRC.
Warning:
If the system expects ALPHA encoding care has to be taken to avoid the possibility that the information
of the Track would have only digits because in this particular case the Adaptor would encode it in BCD.
For instance, a Track carries the room number, some rooms have letters (SUITE1, 301A) but other
rooms have only digits (101, 102). To avoid encode the later in BCD the information in the Track should
always include some fixed character not included in the BCD symbol set, for instance the letter R (for
ROOM) or just a space before or after every room number.
ROM14 code is always ALPHA encoded adding the Start Sentinel (%), End Sentinel (?) and final LRC.
9.3.2 Syncronization zeros
Before and after the data, the Adaptor appends 25 leading and 25 trailing zeros emulating a standard
magnetic card reader.
9.4 WIEGAND formats
Byte and bit order: Wiegand interface sends the data always Most Significant Byte First and Most
Significant Bit First.
Parity bits: The two parity bits are one Even parity bit of the first half bits at the beginning and one
Odd parity bit of the last half bits at the end.
Data for Wiegand is usually ROM code and Serial Number, notice that they are not exactly the same,
please find in ROM code and Serial Number the relation between them.
In some configurations Wiegand uses the same formats BCD and ALPHA of the OMRON interface. It
sends the bits in the same order they would be sent through the OMRON (Clock and Data) interface, but
without adding leading and trailing zeros.
10 Card Technologies
The Desktop Reader and Wall Reader Adaptor are available for all RW technologies: iButton, Smart
Cards and Proximity. There are some few exceptions:
•ArenaCards (NAGRA) are not included because they cannot carry Tracks or Wiegand Code,
neither do have ROM code.
•I2C smart cards have no ROM Code but can have Track 1, 2 and 3 and Wiegand Code.
•In Legic cards the systems can only read the ROM code of cards with a Salto segment.
11 BCD and ALPHA ISO Standards
The data of tracks 1, 2 and 3 of magnetic stripe cards can be encoded in two ways: BCD and ALPHA
formats.
11.1 BCD Data Format (ANSI/ISO)
It is used in Track 2 and Track 3.
Set of characters: 16 characters of 5 bits (4 bits + odd parity). LSB first (Least Significant Bit first) and
Parity Bit last. BCD Value = ASCII value – 0x30.
11.2 ALPHA Data Format (ANSI/ISO)
It is used by Track 1.
Set of characters: 64 characters of 7 bits (6 bits + odd parity). ). LSB first (Least Significant Bit first)
and Parity Bit last. ALPHA value = ASCII value – 0x20.
