m4a5a_v320_eng (14.02.2013)
- 16 -
Kompetent für Elektroniksysteme
m4a5a_v320_eng (14.02.2013)
- 17 -
Kompetent für Elektroniksysteme
Decoder
Major 4a/5a contains 10 decoders that are freely programmable by 3 registers for each of the de-
coders (see Table of Registers, registers 020-049). If the Major is set to factory defaults, an alarm
tone signalizes a decoded call. Furthermore, the loudspeaker is activate, its LED flashes, the alarm
output (switching output 7) is switched and the standard acknowledgement is sent (only decoder 0,
all the others are not active).
The corresponding registers:
Register 020 - 029
: tone sequences and activation/deactivation of the respective decoder
Register 030 - 039
: actions upon decing a call, alarm tone, volume
Register 040 - 049
: ID mode (type of tone sequence, call->ID-code / ID-code->call,...)
switching outputs, loudspeaker, display, emergency call flag
Every single decoder can be configured independently. Starting with decoder 1, the received tone
sequence is compared to the stored tone sequence. If the sequence is recognized positively by the
decoder, no further decoding of the other decoders is performed. If the tone sequence is not recog-
nized by decoder 1 it is compared to the sequence stored in decoder 2. This routine is repeated for
all decoders until decoding is successful or until comparison to the last decoder is performed.
The alarm tone can be programmed separately for each decoder (see Table of Registers, registers
030-039). The alarm tone is an alternating sequence of two tones with different frequencies. Upon
calling the alarm tone can be set to a defined volume for a certain time. This can be an explicit
value between 0 and 9 or a volume increase of 0 to 5 steps (programmed as A to F). The duration
of the volume increase can be set from 0 to 3 s in 200 ms steps.
Register 030 - 039
1
st
digit: alarm tone
1 = 600/675Hz
6 = 1100/1375Hz
2 = 800/900Hz
7 = 500/750Hz
3 = 1000/1125Hz
8 = 1000/1500Hz
4 = 700/875Hz
9 = 700/1283Hz
5 = 900/1125Hz
0 = no alarm tone
B = 600/675Hz, 10 repetitions
C = 800/900Hz, 10 repetitions
D = 1000/1125Hz, 10 repetitions
E = 700/875Hz, 10 repetitions
F = 900/1125Hz, 10 repetitions
2
nd
digit: duration
0 to F: n* 200ms, corresponding to 0 to 3s
3
rd
digit: call volume
0 to 9: constant volume, A to F: volume increased by 0 to 5 steps