Matrix Orbital LK202-25 Legacy User Manual
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Auto Scroll On
ASCII 'Q', Hex 51, Decimal 81
Syntax 0xFE 0x51
To enable auto scroll, send a command prefix followed by the character ‘Q’.
Auto Scroll Off
ASCII 'R', Hex 52, Decimal 82
Syntax 0xFE 0x52
When auto scrolling is disabled, text will wrap to the top left corner of the display area.
Auto Transmit Keypresses On
ASCII 'A', Hex 41, Decimal 65
Syntax 0xFE 0x41
To activate the automatic transmission of keypresses, send a command prefix followed by the character 'A'. In this mode, all
keypresses are sent immediately to the host system without the use of poll keypad command. This is the default mode on
power up.
Auto Transmit Keypresses Off
ASCII 'O', Hex 4F, Decimal 79
Syntax 0xFE 0x4F
To disable the automatic transmission of keypresses, send a command prefix followed by the character 'O'. In this mode, up
to 10 keypresses are buffered until the unit is polled by the host system via the poll keypad command.
Poll Keypad
ASCII '&', Hex 26, Decimal 38
Syntax 0xFE 0x26
To return any unbuffered keypresses via the RS - 232 interface, send a command prefix followed by the character '&' and
then set up the host system to receive the key codes. When a keypad module receives this command it will immediately
return any unbuffered keypresses which may have not been read already. If there is more than one keypress buffered, then
the high order bit of this returned keycode will be set. If this is the only buffered keypress, then the high order bit will be
cleared. If there are no buffered keypresses, then the returned code will be 0x00.
Enter Buffer Return Status Mode
ASCII ‘:’, Hex 3A, Decimal 58
Syntax 0xFE 0x3A
To enter buffer return status mode, send a command prefix followed by the character ‘:’. The module will now wait for the
two bytes which define the parameters: Where
unit sends a “buffer is almost full” message to the host system, and where
bytes that will be left in the buffer when the unit sends a “buffer is almost empty” message.
Entering this mode tells the host system when the buffer of the display is almost full or almost empty. When the data being
sent to the module reaches the user defined value of almost full, the module will relay the message 0xFE to the host system.
The module will also relay this message for every byte that overruns the limit defined by the value for . When the buffer is
almost empty the module will then relate back to the host system the message 0xFF, this informs the host system that the
buffer is almost empty.
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