Dolby Laboratories DP524 - Manual (Page 31)

6-5
6.3 Serial Control
It is possible to command the DP524 via the RS-232 port, J105 on the rear of the
unit when the Command/Aux data switch (S101-4) is in the Up position. The
communications protocol for command mode is fixed at 9600 baud, 1 stop bit, no
parity.
Note This port cannot be used simultaneously for external control and Auxiliary Data output.
The unit expects to receive a five byte sequence and responds in one of the
following ways:
x
If the command sequence is not expecting to return a value (as in the case
of Enable Test Tone) then successful receipt of the command is responded
with a single ASCII character '*'.
x
If the command sequence is not received correctly (for example the stop
byte $FD is corrupted) then the unit responds with a single ASCII character
'?'.
x
If the command is expecting a reply (as in the case of Return Status) then
that status byte is returned.
The data sequence is as follows ($ prefix denotes hexadecimal notation):
6.3.1 System related commands
The following commands are system commands and will be responded to
regardless of the algorithm currently loaded.
Command $14: Enable/Disable Test Tone
$FB $20 $14 data $FD
Where data is as follows:
B7 B6 B5 B4 B3 B2 B1 B0
Enable 0 0 0 SR2 SR1 0 0
Enable, SR2 and SR1 are defined as follows:
SR1 SR2 Enable Comment
X X 0 Test Tone Disabled
0 0 1 48kHz Sample Rate, 1125Hz Tone
1 0 1 44.1Khz Sample Rate, 1033Hz Tone
0 1 1 32kHz Sample Rate, 750Hz Tone
1 1 1 Illegal
Note:
This command will only be accepted if the DIP switch controlling the Test Tone
(S101-1) is set for normal operation. If S101-1 is set active, this command will
respond with a '?' instead of '*'.
MAIN