
Myryad System Ltd.
MDP 500 Preamplifier
Processor RS-232 command
set
Version MDP500-2.2, (applies to S/N
1794 and thereafter) 5.7.2001
(for
earlier serial numbers, see here
for alternative command set)
Technical specification
9600bps , 8 data bits, one stop bit,
no parity binary transmission, no flow control.
Important: An external Baud
Rate Converter is required in order to use the RS-232 interface. It
is needed because the MDP 500’s internal clock is not related to the
standard RS-232 data rates. Baud Rate Converters are available from
Myryad Systems.
RS-232 baud rate converter and
connectors
Baud Rate Converter: This is
a small self-contained module which is fitted between the MDP 500 and
the system controller, dimensions approximately 63x54x16mm. It has 25-pin
“D” i/o connections. The male connector goes towards the MDP 500 and
the female towards the system controller.
The RS-232 pin connections are as follows:
MDP 500
9 pin i/o (female)
|
Signal
|
Baud Rate Converter
25 pin i/o (male/female)
|
1
|
+5V
|
8
|
2
|
Tx out
|
3
|
3
|
Rx in
|
2
|
4
|
No connection
|
|
5
|
Ground
|
7
|
6
|
No connection
|
|
7
|
No connection
|
|
8
|
No connection
|
|
9
|
No connection
|
|
Input commands
Each user input command must be preceded
by the “RS_ENABLE _CONTROL” command which is a string of four bytes:
<224><82><83><33>
The following user input commands are
all single bytes sent to the MDP 500’s RS-232 port. They create various
output data depending on the system status, so a comprehensive output
data feedback can’t be given.
Note: All command and data bytes
are given in decimal format.
RS-232 Byte
|
MDP 500 User Command
|
Description (if not MDP 500 User Command) or additional information
|
Internal System Command
Name
|
6
|
STANDBY
|
Toggle function
|
UI_STANDBY_TOGGLE
|
7
|
MUTE
|
Toggle function
|
UI_MUTE
|
8
|
SOURCE +
|
|
UI_SOURCEPLUS
|
9
|
SOURCE –
|
|
UI_SOURCEMINUS
|
10
|
MODE –
|
|
UI_MODEMINUS
|
11
|
MODE +
|
|
UI_MODEPLUS
|
12
|
COMP
|
|
UI_COMPRESSION_TOGGLE
|
13
|
AUX 2
|
|
UI_AUDIO_IN1
|
14
|
AUX 1
|
|
UI_AUDIO_IN2
|
15
|
SAT
|
|
UI_AUDIO_IN3
|
16
|
VCR
|
|
UI_AUDIO_IN4
|
17
|
TV
|
|
UI_AUDIO_IN5
|
18
|
DVD
|
|
UI_AUDIO_IN6
|
19
|
CD
|
|
UI_AUDIO_IN7
|
20
|
TUNER
|
|
UI_AUDIO_IN8
|
23
|
TEST
|
Enter TEST (Noise) mode – toggle
function
|
UI_NOISE
|
24
|
LEVEL
|
Enter LEVEL mode (as R/C command)
|
UI_LEVEL
|
25
|
DELAY
|
Enter DELAY mode (as R/C command)
|
UI_DELAY
|
31
|
TAPE MONITOR
|
Toggle function
|
UI_TAPEMON_NONSTICKY_TOGGLE
|
32
|
|
MUTE ON – not toggle function
|
UI_MUTE_ON
|
33
|
|
MUTE OFF – not toggle function
|
UI_MUTE_OFF
|
34
|
|
Switches to Standby – not toggle
function
|
UI_STANDBY
|
35
|
|
Switches out of Standby – not
toggle function
|
UI_WAKEUP
|
37
|
|
COMP ON – not toggle function
|
UI_COMPRESSION_ON
|
38
|
|
COMP OFF – not toggle function
|
UI_COMPRESSION_OFF
|
39
|
|
TAPE MON ON – not toggle function
|
UI_TAPEMON_OFF
|
41
|
|
TAPE MON OFF – not toggle function
|
UI_TAPEMON_NONSTICKY_ON
|
42
|
|
Go to MONO mode
|
UI_MONO
|
43
|
|
Go to STEREO mode
|
UI_STEREO
|
44
|
|
Go to DOLBY PRO LOGIC mode
|
UI_PROLOGIC
|
45
|
|
Go to NATURAL music mode
|
UI_MUSIC1
|
46
|
|
Go to CLUB music mode
|
UI_MUSIC2
|
47
|
|
Go to CONCERT music mode
|
UI_MUSIC3
|
48
|
|
Go to PARTY music mode
|
UI_MUSIC4
|
49
|
VOL +
|
|
REMOTE_VOLUME_PLUS
|
50
|
VOL –
|
|
REMOTE_VOLUME_MINUS
|
53
|
|
Volume +/- as front panel control.
Does not de-mute in MUTE mode.
|
FRONTPANEL_VOLUME_PLUS
|
54
|
|
FRONTPANEL_VOLUME_MINUS
|
68
|
|
Increase BASS setting by 1dB
|
UI_BASS_PLUS
|
69
|
|
Decrease BASS setting by 1dB
|
UI_BASS_MINUS
|
70
|
|
Increase TREBLE setting by 1dB
|
UI_TREBLE_PLUS
|
71
|
|
Decrease TREBLE setting by 1dB
|
UI_TREBLE_MINUS
|
96
|
|
Go to SPEAKER (Bass Management)
setup mode
Speaker size set using TRIM +/-
|
UI_SPEAKER
|
97
|
|
Increase SUBWOOFER level setting
by 1dB
|
UI_SUBWOOFER_PLUS
|
98
|
|
Decrease SUBWOOFER level setting
by 1dB
|
UI_SUBWOOFER_MINUS
|
99
|
CINE EQ
|
Toggle function
|
UI_CINE_EQ_TOGGLE
|
101
|
TRIM +
|
These commands operate in LEVEL
and DELAY modes only and after Command #96.
|
UI_TRIM_PLUS
|
102
|
TRIM –
|
UI_TRIM_MINUS
|
103
|
MENU
|
Toggle function
|
UI_OSD_SETUP
|
104
|
CURSOR UP
|
|
UI_CURSOR_UP
|
105
|
CURSOR DOWN
|
|
UI_CURSOR_DOWN
|
106
|
CURSOR LEFT
|
|
UI_CURSOR_LEFT
|
107
|
CURSOR RIGHT
|
|
UI_CURSOR_RIGHT
|
108
|
SELECT
|
|
UI_CURSOR_ENTER
|
109
|
EXIT
|
|
UI_ESCAPE
|
122
|
STATUS
|
|
UI_OSD_STATUS
|
133
|
E-BASS
|
Toggle function
|
UI_BASS_MIX_TOGGLE
|
136
|
7.1 CHANNEL
|
Toggle function
|
UI_AUDIO_IN_EXT71_TOGGLE
|
Direct volume setting
In addition the Master volume may be
set directly using the command UI_SET_VOLUME.
The format of this command is:<224><82><83><33>
(as before)
followed by:
<180><data>
<data> = 10…100 where 10 = -90dB,
100 = 0dB
(0dB is maximum direct setting for
reasons of safety)
Output data
The following data (in the table below)
are sent out to the RS-232 port whenever the status of the current parameter
or function is changed. The output data consist of at least three bytes:
<command> <data> <EOT>. For example when the Master
Volume is changed to –25dB the following three bytes are sent out: 225
75 255.
Alternatively, the full set of output
data may be requested without changing any parameter by using the RS_QUERY_SYSTEM_STATUS
command. The protocol for this command is to send the single byte <227>.
The MDP 500 will then return two header bytes <223><255>
followed by all of the output data items listed below in sequence. The
communication will thus be:
Controller sends byte <227> to
MDP
MDP returns with:
<223>, <255>
// header
<225>, <vol>, <255>
// RS_VOLUME
……
……
<249>, <TV-system>, <255>
// RS_TV_SYSTEM
Output Data Name
|
RS-232 Byte
|
Function and data
range
|
<data>
|
RS_VOLUME
|
225
|
Master volume: <data> =
10…120
|
10 = -90dB, 100 = 0dB, 120 = +20dB
|
RS_MUTE
|
226
|
Mute: <data> = 0/1
|
0 = unmuted, 1 = muted
|
RS_AUDIO_SOURCE
|
227
|
Source: <data> = 1…8
|
1…8 = Source number
|
RS_VIDEO_SOURCE
|
228
|
Composite/SVIDEO video source:
<data> = 1…6
|
1…6 = Source number
|
RS_OPER_MODE
|
229
|
<data> = 0/1
|
0 = Standby, 1 = on
|
Not used
|
230
|
<data> = 1….16
|
|
Not used
|
231
|
<data> = 1….6
|
|
Not used
|
232
|
<data> = 10….115
|
|
Not used
|
233
|
<data> = 0/1
|
|
Not used
|
234
|
<data> = 0/1
|
|
RS_TAPEMONITOR
|
235
|
TapeMonitor status: <data>
= 0/1
|
0 = TapeMonitor off
1 = TapeMonitor on
|
RS_STEREO_MODE
|
236
|
Stereo mode: <data> = 0…10
|
0 = Stereo
1 = Dolby Pro Logic
2 = Natural
3 = Club
4 = Concert
6 = Party
7 = Mono downmix
10 = Stereo modes not available
|
RS_SIGNAL_TYPE
|
237
|
Audio signal type: <data>
= 0…8
|
1 = silent, zero signal
2 = Digital PCM
3 = Dolby Digital
4 = DTS
6 = Noise (generated by the DSP)
7 = Analog
8 = Digital Error (unrecognized
or corrupted digital signal)
|
RS_AUDIO_INPUT_TYPE
|
238
|
Audio signal physical input type:
<data> = 0…2
|
0 = Analogue
1 = Coaxial
2 = Optical
|
RS_COMPRESSION
|
239
|
Late Night compression status:
<data> = 0/1
|
0 = Compression off
1 = Compression on
|
RS_CINEEQ
|
240
|
Cine EQ status: <data> =
0/1
|
0 = Cine EQ off, 1 = Cine EQ on
|
RS_VIDEO_INPUT_TYPE
|
241
|
Type of input video signal:
<data> = 0…2
|
0 = unknown / no input signal
1 = Composite
2 = S-Video
|
RS_TREBLE
|
242
|
Treble equalizer: <data>
= 0…24
|
0 = -12dB, 12 = 0dB, 24 = +12dB
|
RS_BASS
|
243
|
Bass equalizer: <data> =
0…24
|
0 = -12dB, 12 = 0dB, 24 = +12dB
|
RS_CENTRE
|
244
|
Centre trim level: <data>
= 0…24
|
0 = -12dB, 12 = 0dB, 24 = +12dB
|
RS_SURROUND
|
245
|
Surround trim level: <data>
= 0…24
|
0 = -12dB, 12 = 0dB, 24 = +12dB
|
RS_SUBWOOFER
|
246
|
Subwoofer trim level: <data>
= 0…24
|
0 = -12dB, 12 = 0dB, 24 = +12dB
|
RS_TRIGGER1
|
247
|
Trigger 1 status: <data>
= 0/1
|
0 = trigger inactive, 1 = trigger
active
|
RS_TRIGGER2
|
248
|
Trigger 2 status: <data>
= 0/1
|
0 = trigger inactive, 1 = trigger
active
|
RS_TV_SYSTEM
|
249
|
TV system of the video input signal:
<data> = 0…2
|
0 = unknown, 1 = PAL, 2 = NTSC
|
Not used
|
250
|
<data> = 0/1/2
|
|
RS_EOT
|
255
|
Sent out as a last byte of each
transmission from the serial port
|
Please address technical questions to
tech@myryad.co.uk, other inquiries
to:
Myryad Systems Ltd.
2 Pipers Wood, Waterberry
Drive
Waterlooville, Hants,
PO7 7XU
Tel: +44 (0) 23 92265508
Fax: +44 (0) 23 92231407
info@myryad.co.uk
www.myryad.co.uk
Changes in Myryad RS-232 command
set Version MDP-500-2.2
compared with Versions MDP-500-1.2 and earlier.
This document was prepared to aid users
already familiar with RS-232 control of the MDP 500, by highlighting
the areas of change. Version 2.2 applies to MDP 500s with firmware version
2.14 and later (unit serial number 1794 and thereafter).
The firmware version can be confirmed
on these units by holding down the Standby button when switching the
unit on. After holding down the button for a few seconds the display
will indicate the firmware version number. If no number is displayed
then the firmware is prior to version 1.07.
All user commands now require the RS_ENABLE_CONTROL
command to be sent before each input command. This means the four bytes
<224><82><83><33> must be sent before each command.
- This feature was added to prevent
errors caused by spurious bytes being sent from PC/controllers’ RS-232
ports – particularly after crashes and re-boots.
- The master volume control level may
now be set directly using the UI_SET_VOLUME command (decimal 180).
- A full set of System Status information
can now be obtained (without changing any parameter) by using the
RS_QUERY_SYSTEM_STATUS command (decimal 227).
- Centre and Surround outputs have been
added to the list of output data (244 and 245) which can be accessed
either by using RS_QUERY_SYSTEM_STATUS or when changing the relevant
parameter.
|