m4_eng(11.03.02)
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Kompetent für Elektroniksysteme
FFSK Identication
If FFSK identication is switched on, a FFSK identication code is transmitted any time the PTT button
is pressed. As ID-code the decoder 1 coding (register 000) is transmitted. The FFSK identication is
switched on at the rst digit of register 032 in EEPROM 1 ('0' = off, '1' = on).
FFSK Emergency Call
If a FFSK telegram with status = emergency call is received, the Major 4 will stop any channel
scanning. The loudspeaker and the handset are switched on, the loudspeaker lamp ashes, the
emergency call ID-code is stored and ashes on the display. As long as an emergency call is
displayed, the keypad is blocked. An emergency call can be deleted by pressing the (F1) key.
FFSK Decoder
At rst, the BAK of every telegram is checked. If the BAK equals to the BAK coded at digit 4 of
register 032 (EEPROM 1), the decoder is released.
The decoder 1 is coded in register 000 (EEPROM 1). See section EEPROM 1 Programming Mode.
The telegram detected is compared with the decoder 1 coding and in case of positions being coded
with 'F', any digit is accepted. If the FFSK telegram has been identied as correct, the loudspeaker
and the handset are switched on, the loudspeaker lamp ashes, the FFSK acknowledgement is
transmitted and the bell tone is started. No further telegram check will be performed.
The decoder 2 is coded in register 007 (EEPROM 1). See section EEPROM 1 Programming Mode.
The telegram detected is compared with the decoder 2 coding and in case of positions being coded
with 'F', any digit is accepted. If the FFSK telegram has been identied as correct, the loudspeaker
and the handset are switched on, the loudspeaker lamp ashes and the bell tone is started. No further
telegram check will be performed. An acknowledgement is not transmitted.
FFSK Acknowledgement
After detection by decoder 1 the FFSK acknowledgement is transmitted. The acknowledgement
is coded in register 002 (EEPROM 1). If no acknowledgement is required, digit 1 of register
002 is coded with 'F' (blank).
