ACHAT DSP24 • OWNER’S MANUAL
22
USB/RS485 remote control protocol for preset changing
and gain/volume
The following is the HEX Code for controlling the DSP24 recall
presets and master volume control:
Preset Changing:
CMD_RECALL_PRESET: CMD=1BH
A. The User has to send the following Command, including the
number of the preset to load on the unit:
TX:
STX
ID_M
ID_N
CMD
D0
D1
D2
D3
D4
D5
D6
D7
ETX
FOH
C1H
XX
1BH NPreset 00H 00H 00H 00H 00H 00H 00H F7H
XX = 0,..,31 (ID device)
Npreset=01,...,25 Presetnumber
The DSP24’s micro controller will check if the preset is initialized
(available or not yet created...)
B. If YES, then the micro controller will send back to the user
(eg Crestron/AMX Remote Control..) the same frame used
by the command
RX:
STX
ID_M
ID_N
CMD
D0
D1
D2
D3
D4
D5
D6
D7
ETX
FOH
C1H
XX
1BH NPreset 00H 00H 00H 00H 00H 00H 00H F7H
So in this case, if the user gets back EXACTLY what was sent,
the preset is existing and loaded on the unit.
C. If the preset that the user wanted to load is NOT YET
INITIALIZED (not yet created, so not available...). the
micro controller will notify that to the user, sending back
the following frame:
RX:
STX
ID_M
ID_N
CMD
D0
D1
D2
D3
D4
D5
D6
D7
ETX
FOH
C1H
XX
1BH
FFH
00H
00H
00H
00H
00H
00H
00H
F7H
Input gain and output volume control:
UPDATE GAINS-PHASE: CMD=01H
A. The user has to send the following command, including the
value to be assigned to “Vol”, for modifying the input gain
(Chn = 0, 1) or the output volume (Chn = 2, 3, 4, 5).
Also the output signal phase can be modified:
TX:
STX
ID_M
ID_N
CMD
D0
D1
D2
D3
D4
D5
D6
D7
ETX
FOH
C1H
XX
01H
Chn
00H
00H
00H
00H
00H
Phs
Vol
F7H
XX = 0,..,31 (ID device)
Chn=0,...,5: channel selected, 0, 1=In1, In2; 2,...,5=Out1,..,Out4;
when channel 0, 1 selected, then Vol=Input gain,
when channel 2, 3, 4, 5 selected, then Vol=output Vol.
Phs= Phase only if the Chn>1; Value=0, 1 where 0=direct,
1=inverse (180°)
Vol= gains from 0 to 180 (-12dB/ +6dB step 0.1dB)
B. If the command has been properly executed and the gain/
Volume modified, then the micro controller will send back
to the User (eg Crestron/AMX Remote Control.) the same
frame used by the command:
RX:
STX
ID_M
ID_N
CMD
D0
D1
D2
D3
D4
D5
D6
D7
ETX
FOH
C1H
XX
01H Chm 00H
00H
00H
00H
00H
Phs
Vol
F7H