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SECTION 3. COMMANDS, FORMATS, TIMING
This section includes commands from the Host to the Reader, Reader to Host message formats,
transmission timing, and possible uses of drivers.
HOST TO READER COMMANDS
All commands transmitted from the Host to the Reader must be preceded by the ASCII “ESCAPE”
character. These command messages may contain other framing characters, which are ignored by the
Reader. Table 3-1 describes I and R commands, a switch selectable option for the ASCII command
character and the Reader response to the Host. Table 3-2 describes the second character commands
Table 3-1. Commands and Responses - I and R Commands
HOST COMMANDS
READER RESPONSES
ASCII “ESCAPE”
CHARACTER
(1B hex)
SWITCH SELECTABLE ASCII
CHARACTER - SWB4
ON
OFF
<ESC>
I
+
Inquiry command causes the
Reader to transmit data, error, or
status message.
<ESC>
R
-
Release command causes the
Reader to clear its memory buffer of
any data present. This command
works only in the Buffered mode.
Table 3-2. Commands and Responses – Auxiliary Driver Commands
ASCII “ESCAPE”
CHARACTER
(1B hex)
ASCII SECOND
CHARACTER
READER RESPONSES
<ESC>
0
Deactivates both user drivers 1 and
2.
<ESC>
1
Activates user driver 1.
<ESC>
2
Activates user driver 2.
<ESC>
3
Deactivates user driver 1.
<ESC>
4
Deactivates user driver 2
READER TO HOST FORMATS
The following diagrams represent the formats of the data transmitted after a successful card read, an
unsuccessful card read, and no card read which is the response if the Host inquires and the buffer is
empty.
