Magtek MICRSafe, Техническое справочное руководство

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Section 5. USB Communications
39
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, and finally 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 set in
the key map. This can be any value
between 0 and 127 (0x7F). For example,
to set the key map item for ASCII character
‘?’ (card data end sentinel) use the ASCII
value of ‘?’ which is 63 (0x3F).
1 Key Usage ID The value of the USB key usage ID that is
to be 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 ‘?’. To change this to the ASCII
character ‘>‘ use usage ID 55 (0x37)
(keyboard . and >).
2 Key Modifier Byte The value of the USB key modifier byte
that is to be 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 ‘?’. To
change this to the ASCII character ‘>‘ use
modifier byte 0x02 (left shift key).
Response Data: None
Result codes: 0 (success)
The following example maps the card ASCII data end sentinel character ‘?’ to the ‘>’ keyboard
key.
Example Request (Hex):
Cmd Num Data Len Data
04 03 3F 37 02
Example Response (Hex):
Result Code Data Len Data
00 00