MagTek P-SERIES USB - Manual (Page 62)

P-Series USB Insertion Reader
54
SET KEYMAP ITEM COMMAND
Command number:
4
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 device 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.
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.