Magtek MagneSafe V5, Reference Manual

Page: 69 / 138

Section 2. Communications
61
Response Data:
Offset Field Name Description
0 Key Usage ID The value of the USB key usage ID that is
mapped to the given ASCII value. For
example, for the United States keyboard
map, usage ID 56 (0x38) (keyboard / and
?) is mapped to ASCII character ‘?’.
1 Key Modifier Byte The value of the USB key modifier byte
that is mapped to the given ASCII value.
For example, for the United States
keyboard map, modifier byte 0x02 (left
shift key) is mapped to ASCII character ‘?’.
Result codes:
0x00 Success
Example Request (Hex):
Cmd Num Data Len Data
03 01 3F
Example Response (Hex):
Result Code Data Len Data
00 02 38 02
Set Keymap Item Command (KB)
Command number: 0x04
Description: This command is used to set a key map item of the active key map. The
active key map is determined by the active key map property. Data from a
magnetic stripe card is a sequence of ASCII characters. These ASCII
characters are mapped to key strokes and these key strokes are sent to the
host to represent the ASCII character. The key map maps a single ASCII
character to a single USB key usage ID and USB key modifier byte. The
key usage ID and the key modifier byte are transmitted to the host via
USB to represent the ASCII character. The ASCII value is the value of
the ASCII character to be transmitted to the host. See an ASCII table for
the values of the ASCII character set. The USB key usage ID is a unique
value assigned to every keyboard key. For a list of all key usage IDs see
Appendix A. The key modifier byte modifies the meaning of the key
usage ID. The modifier byte indicates if any combination of the right or
left Ctrl, Shift, Alt or GUI keys are pressed at the same time as the key
usage ID. For a list and description of the key modifier byte see Appendix
B. Once a key map item is modified, the changes take affect immediately.
However, the changes will be lost if the reader is reset or power cycled.
To make the changes permanent, the save custom key map command must
be issued. To use the new custom key map after a reset or power cycle,
the active key map property must be set to custom.