Specifications

Section 3. Commands, Formats, Timing
15
Where
SS = Start Sentinel: "%" for Track 1; ";" for Track 2; "+" for Track 3
Data = Track Data in track order
that is, Track 1 then Track 2 or Track 2 then Track 3
ES = End Sentinel: "?"
Sensor = "0" no card in reader
"1" card present in reader (rear sensor blocked)
If there is an error in one of the tracks, the "Track Data" field will be replaced with "E" (0x45).
An example of a card insertion or removal is as follows:
STX ESC 1 CR ETX
Optional
Where
1 = Sensor blocked
0 = Sensor unblocked
The following is an example of a good read on withdrawal of a card:
Where 0 represents the sensor unblocked.
STX ESC % Track 1 Data ?
;
Track 2 Data ? 0 CR ETX
Optional
The following is an example of a bad read on Track 1 and a good read on Track 2 on withdrawal
of a card:
STX ESC % E ?
;
Track 2 Data ? 0 CR ETX
Optional
Where
E (0x45) = Error
Track 2 Data = Good read Track 2 Data
0 = Sensor unblocked