MagTek USB INSERTION READER - Manual (Page 62)

USB Insertion Reader
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When both the key usage ID and the key modifier byte are set to 0xFF for a
given ASCII value, the ALT ASCII code is sent instead of the key map
values. The ALT ASCII code is a key press combination consisting of the
decimal value of the ASCII character combined with the ALT key
modifier. For example, to transmit the ASCII character ‘?’ (063 decimal),
keypad ‘0’ is sent combined with left ALT key modifier, next keypad ‘6’ is
sent combined with the left ALT key modifier, last keypad ‘3’ is sent
combined with the left ALT key modifier.
Data structure:
Request Data:
Offset Field Name Description
0 ASCII value Value of the ASCII character to be
retrieved from the key map. This can be
any value between 0 and 127 (0x7F). For
example, to retrieve the key map item for
ASCII character ‘?’ (card data end
sentinel) use the ASCII value of ‘?’ which
is 63 (0x3F).
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: 0 (success)
Example Request (Hex):
Cmd Num Data Len Data
03 01 3F
Example Response (Hex):
Result Code Data Len Data
00 02 38 02