Programming The Leds - Siemens SCD 1297-K (33) Operating Instruction

3.2.2

Programming the LEDs

The foil keyboard has 39 LEDs which are arranged in combination with some of the keys.
These LEDs can be used, for example, as receipt or ready signals.
The LEDs are switched via the keyboard connection between the computer and the control
panel, in a similar manner to the programming of the keys. A special command has been
implemented for driving the LEDs since, in the MF2 specification; there are only NumLock,
CapsLock and ScrollLock LEDs. This command enables the individual LEDs to be switched
on and off.
The correlation between LED number and LED position is shown in Fig. 7, page 63.
The special command for the LED data is 0xEA followed by 10 Bytes with LED-Information.
Protocol
0xEA B1H B1L
0xEA : Special command
B1-B5 : LED information in ASCII-Hex format (H= high, L=low)
Important: Each of the LED bytes, B1 to B5 is in ASCII hex format, i.e. for each LED byte,
'Bx', two bytes of data are transmitted.
For each byte that the control panel receives from the computer, a receipt byte (oxFA) is sent
back.
Control panel SCD 1297-K
B2H B2L B3H
Page 53 / 64
B3L B4H B4L
Operating instruction
B5H B5L
DOC-Nr.: b40008de3.doc