Harman Kardon SIGNATURE 2.0 Installation instructions manual

SIGNATURE 2.0
SIGNATURE 2.0 BUS PROTOCOL
INSTRUCTIONS & OPERATION MANUAL
MASTER DOCUMENT
VERSION 1.0

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 2of 20
TABLE OF CONTENTS
Software Revision History _________________________________________________ 3
How Does It Work? _______________________________________________________4
Event Driven Output ______________________________________________________ 4
Protocol Format __________________________________________________________5
Sample Message _________________________________________________________ 7
Direct Commands ________________________________________________________ 8
Response Commands _____________________________________________________ 31
Unsolicited Commands ___________________________________________________ 43

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 3of 20
SOFTWARE REVISION HISTORY
The following is a list of the software revisions from the first version of software to include RS-
232 control to the most current version. Verify the version of software in your unit by viewing the
VFD (Vacuum Fluorescent Display) on the front panel immediately after you apply power to the
Signature 2.0 (main power, not standby).
Version 2.5: First release.

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 4of 20
How Does It Work?
The Signature Communication Protocol is designed specifically for controlling audio and video
equipment. It was developed in response to a need for a low-cost, simple, fault-tolerant
communications protocol. It is based on the EIA RS-232 electrical specification. Data is
communicated at 9600 baud,8 data bits,1 stop bit and no parity.
Before beginning data transmission, check the bus for inactivity. If the bus is free, transmission
may commence. If the bus is being used, wait for a period of inactivity. Check each byte of a
transmission against the intended message to ensure that data corruption does not occur due to
multiple devices attempting to use the bus at the same time. For each message received, the
receiver will generate an acknowledgment. The device which sent the message should receive this
acknowledgment before beginning its next data transmission. Under rare circumstances, the
receiver may be performing a function which cannot be interrupted. The message should be
retransmitted until an acknowledgment is received. Due to this fact, delays are required between
incoming messages for the transmission of the required acknowledgment.
Event Driven Output:
The Signature 2.0 will generate commands when the processor is accessed from an IR or Front
panel button command. This command can be used to update external displays in real time or to
generate a polling request for status.
The command generated will be identical to the Signature bus command for the same function,
but it will have a different Target Device Type and Command Modifier. Example: the IR “Vid 1”
button on the remote will generate a “Vid 1” button command on the Signature bus. See page ??
of this document for a list of the Remote Button codes.
Volume level updates from the Front Panel rotary encoder are handled slightly differently. When
a volume adjustment is made, the 2.0 will wait for a period of encoder inactivity and then transmit
an unsolicited “Power/Volume Status” response. See page ??.

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 5of 20
PROTOCOL FORMAT
Note: the symbols “b”, “d”, and “h” used in this document denote binary, decimal, and hexadecimal values,
respectively. All transmissions must be in hexadecimal.
The Preamble is a byte used to alert the system that a message is about to
be transmitted. This allows the system to ignore random noise, and
reliably receive valid messages. The Preamble is always equal to 7Eh.
NOTE:
No other byte in any part of the message may equal 7Eh.
The Target Device Type is a byte that distinguishes what type of unit the
message is intended for (i.e. a preamp versus a CD player).
HEX Device Type
01 Audioaccess KPS keypad
04 Audioaccess Computer
05 Audioaccess Paging/SMM Module
06 Audioaccess PX-603
07 Audioaccess Internal Multi
20 Signature 2.0 Processor/Tuner
30 Signature 3.0 DVD player
50 Citation 5.0 AV Controller
70 Citation 7.0 AV Controller
99
Broadcast Message (everyone listens)
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
The Target Unit ID is a byte that distinguishes which unit of a given type
the message is intended for (i.e. CD player #1 versus CD player #2). The
Unit ID is set in the menu system of the unit you are trying to control,
default = 01h. If you are using more than one of any given unit, you will
need to modify this byte to reflect the ID number of the unit you are trying
to control.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
The Source Device Type is a byte that distinguishes what type of unit the
message is coming from (i.e. a preamp versus a CD player). See above
list.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 6of 20
The Command Modifier is a byte that distinguishes what type of command
is being sent.
HEX Command Type
01 Action request
02 Action response
Provides additional information required by the Command byte.
The Command byte is the action that is desired.
The Data Length is a word representing the total number of bytes
(including Command Modifier and Command bytes, but not the Data
Length byte itself or the Checksum byte) in the data portion of the
message. Minimum length is 02h.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
The Source Unit ID is a byte that distinguishes which unit of a given type
the message is coming from (i.e. CD player #1 versus CD player #2). The
Unit ID is set in the menu system of the unit that the message is coming
from, default = 01h. If you are using more than one of any given unit, you
will need to modify this byte.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
Provides additional information required by the Command byte.
The Data bytes consist of information that is required to complete the
Command. The Data bytes are detailed throughout the rest of this
document.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
Provides additional information required by the Command byte.
The Checksum is a byte whose value confirms/voids the validity of a
received message. It is computed by adding up all of the bytes Preamble
through the last Data byte, and then taking the 1s complement of the lower
eight bits of that sum (i.e. add up all the bytes, truncate to eight bits, and
invert each of the bits). If the result equals 7Eh, add 01h. See the page 7
for an example.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 7of 20
EXAMPLE OF MESSAGE CREATION
Create a Power On command from a Signature 3.0 to a Signature 2.0
in a single 2.0 / single 3.0 system.
Preamble = 7Eh
Length = 03h
Modifier = 01h
Target Device Type = 20h
0111 1110b(7Eh)
0010 0000b(20h)
0000 0001b(01h)
0011 0000b(30h)
0000 0001b(01h)
0000 0011b(03h)
0000 0001b(01h)
0000 0010b(02h)
+ 0000 0001b(01h)
0 1101 0111b(sum = 0D7h)
1101 0111b(truncating = D7h)
0010 1000b(inverting bits = 28h)
0010 1000b(28h ≠7Eh, so don’t add 01h)
Checksum = 28h
Command = 02h
Target Unit ID = 01h
Source Device Type = 30h
Source Unit ID = 01h
Data = 01h
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
03
h
7E
h
02
h
01
h
28
h

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 8of 20
ACKNOWLEDGMENT
COMMAND:
ACKNOWLEDGE:
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
Computed
7E
h
Command
Data
See page 7
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
20
h
30
h
01
h
01
h
02
h
02
h
7E
h
See Below
None
See page 7
The acknowledge Command Byte is formed by adding 80hto the received Command Byte.
Example:
HEX COMMAND DESCRIPTION
05 Command to Mute
85 Acknowledge
The receiving unit transmits the “Acknowledge” response to let the sending unit know that
the message has been successfully received.
The Data Byte(s) are not included in the Acknowledge message.
An Acknowledge is required after EVERY message sent, in either direction.

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 9of 20
EXAMPLE OF MESSAGE EXCHANGE
COMMAND:
ACKNOWLEDGE:
RESPONSE:
ACKNOWLEDGE:
The Signature 3.0 starts by sending a Request for Software
Version command to the Signature 2.0
in a single 3.0 / single 2.0 system.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
02
h
7E
h
77
h
None
35
h
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
20
h
30
h
01
h
01
h
01
h
02
h
7E
h
F7
h
None
35
h
The Signature 2.0 acknowledges by sending an Acknowledge of
Request for Software Version command to the Signature 3.0
in a single 3.0 / single 2.0 system.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
20
h
30
h
01
h
01
h
02
h
04
h
7E
h
77
h
0205
h
2D
h
The Signature 2.0 then sends a Response to Request for
Software Version command to the Signature 3.0 with data of rev. 2.5
in a single 3.0 / single 2.0 system.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
02
h
02
h
7E
h
F7
h
None
34
h
The Signature 3.0 then acknowledges by sending an Acknowledge of
Response to Request for Software Version command to the Signature 2.0
in a single 3.0 / single 2.0 system.

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 10 of 20
BUTTON EMULATION COMMAND
POWER COMMAND
HEX COMMAND DESCRIPTION
01 POWER ON
02 STANDBY
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
03
h
7E
h
02
h
See Below
See page 7
HEX COMMAND DESCRIPTION
00 MONO BUTTON
01 BALANCE BUTTON
02 BACK BUTTON
03 BASS EQ BUTTON
04 FFWD BUTTON
05 REW BUTTON
06 STEREO BUTTON
07 TREBLE BUTTON
08 VOL DWN BUTTON
09 MENU BUTTON
0A ENTER BUTTON
0B PAN BUTTON
0C RIGHT BUTTON
0D VID1 BUTTON
0E VID2 BUTTON
0F UP BUTTON
10 LEFT BUTTON
11 VID3 BUTTON
12 DOWN BUTTON
13 TUNER BUTTON
14 CENTER BUTTON
15 MUTE BUTTON
16 CD BUTTON
17 DISPLAY BUTTON
18 TAPE BUTTON
19 TV BUTTON
1A VOL UP BUTTON
1B POWER ON BUTTON
1C POWER OFF BUTTON
HEX COMMAND DESCRIPTION
1D NUM 0 BUTTON
1E NUM 1 BUTTON
1F NUM 2 BUTTON
20 NUM 3 BUTTON
21 NUM 4 BUTTON
22 NUM 5 BUTTON
23 NUM 6 BUTTON
24 NUM 7 BUTTON
25 NUM 8 BUTTON
26 NUM 9 BUTTON
27 STORE BUTTON
28 RDS BUTTON
29 TYPE BUTTON
2A PSET BUTTON
2B MUSIC BUTTON
2C MOVIES BUTTON
2D SIMUL BUTTON
2E DSK TRK BUTTON
2F AUX BUTTON
30 REC BUTTON
31 PSET UP BUTTON
32 PSET DWN BUTTON
33 FRONT PANEL ON OFF BUTTON
34 FRONT PANEL SOURCE UP BUTTON
35 FRONT PANEL SOURCE DWN BUTTON
36 FRONT PANEL MODE UP BUTTON
37 FRONT PANEL MODE DWN BUTTON
38 FRONT PANEL TUNE UP BUTTON
39 FRONT PANEL TUNE DWN BUTTON
3A FRONT PANEL FP MUTE BUTTON
1A FRONT PANEL VOLUME UP
08
FRONT PANEL VOLUME DOWN
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
03
h
7E
h
01
h
See Below
See page 7
. . . . . . . NOTE . . . . . . .
This command should be used
when one unit wants to
emulate a remote control and
control another unit (i.e. this
command should be sent TO
the unit intended to be
controlled, FROM the
controlling unit).

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 11 of 20
MAIN VOLUME LEVEL
MUTE
SYSTEM RESET
HEX COMMAND DESCRIPTION
00 +00 MIN. VOLUME
01 +01
02 +02
03 +03
04 +04
05 +05
06 +06
07 +07
08 +08
09 +09
0A +10
0B +11
0C +12
0D +13
0E +14
0F +15
10 +16
11 +17
12 +18
13
+19
HEX COMMAND DESCRIPTION
14 +20
15 +21
16 +22
17 +23
18 +24
19 +25
1A +26
1B +27
1C +28
1D +29
thru
48 +72
49 +73
4A +74
4B +75
4C +76
4D +77
4E +78
4F +79 MAX.Volume.
. . . . . . . WARNING . . . . . . .
If you are using this feature to
ramp up and down the volume,
you MUST make sure to set
your limits so you do not roll
over to either MAX. or MIN.
volume levels. Speaker damage
will occur if you do roll over to
Max. volume.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
03
h
7E
h
04
h
See Below
See page 7
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
02
h
7E
h
57
h
Not used
See page 7
WARNING: This command resets ALL data to factory defaults. ALL programming will
be lost.
HEX COMMAND DESCRIPTION
01 Mute On
02 Mute Off
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
03
h
7E
h
05
h
See Below
See page 7

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 12 of 20
UNSOLICITED BUTTON COMMAND
HEX COMMAND DESCRIPTION
00 MONO BUTTON
01 BALANCE BUTTON
02 BACK BUTTON
03 BASS EQ BUTTON
04 FFWD BUTTON
05 REW BUTTON
06 STEREO BUTTON
07 TREBLE BUTTON
08 VOL DWN BUTTON
09 MENU BUTTON
0A ENTER BUTTON
0B PAN BUTTON
0C RIGHT BUTTON
0D VID1 BUTTON
0E VID2 BUTTON
0F UP BUTTON
10 LEFT BUTTON
11 VID3 BUTTON
12 DOWN BUTTON
13 TUNER BUTTON
14 CENTER BUTTON
15 MUTE BUTTON
16 CD BUTTON
17 DISPLAY BUTTON
18 TAPE BUTTON
19 TV BUTTON
1A VOL UP BUTTON
1B POWER ON BUTTON
1C POWER OFF BUTTON
HEX COMMAND DESCRIPTION
1D NUM 0 BUTTON
1E NUM 1 BUTTON
1F NUM 2 BUTTON
20 NUM 3 BUTTON
21 NUM 4 BUTTON
22 NUM 5 BUTTON
23 NUM 6 BUTTON
24 NUM 7 BUTTON
25 NUM 8 BUTTON
26 NUM 9 BUTTON
27 STORE BUTTON
28 RDS BUTTON
29 TYPE BUTTON
2A PSET BUTTON
2B MUSIC BUTTON
2C MOVIES BUTTON
2D SIMUL BUTTON
2E DSK TRK BUTTON
2F AUX BUTTON
30 REC BUTTON
31 PSET UP BUTTON
32 PSET DWN BUTTON
33 FRONT PANEL ON OFF BUTTON
34 FRONT PANEL SOURCE UP BUTTON
35 FRONT PANEL SOURCE DWN BUTTON
36 FRONT PANEL MODE UP BUTTON
37 FRONT PANEL MODE DWN BUTTON
38 FRONT PANEL TUNE UP BUTTON
39 FRONT PANEL TUNE DWN BUTTON
3A FRONT PANEL FP MUTE BUTTON
1A FRONT PANEL VOLUME UP
08
FRONT PANEL VOLUME DOWN
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
99
h
01
h
01
h
01
h
03
h
7E
h
71
h
See Below
See page 7
. . . . . . . NOTE . . . . . . .
This command should be used
when one unit wants to
broadcast to all other units
that it has received and acted
upon an IR command (i.e. this
command should be sent TO
all other units in the system, to
let them know that someone
has pushed a button on the
front panel or remote control
and changed something about
the broadcasting unit.)

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 13 of 20
CONTENTS OF NON-VOLATILE MEMORY REQUEST
COMMAND:
RESPONSE:
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
06
h
7E
h
72
h
See below
See page 7
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
20
h
30
h
01
h
01
h
02
h
Computed
7E
h
72
h
See below
See page 7
uint spkr_cfg; // current speaker configuration
uchar spkr_mutes; // mask bits for speaker group muting
char Volume_preset; // power-on volume setting
Spkr_adj_st spkr_adjs; // speaker level adjustments
signed char center_level;
signed char front_right_level;
signed char front_left_level;
signed char back_right_level;
signed char back_left_level;
signed char subwfr_level;
char front_distance;
char cen_distance;
char back_distance;
char source; // currently active source
uint opFlag; // general purpose operational flags
char svidRecSrc; // used when tracking disabled
char compvidRecSrc; // used when tracking disabled
char audRecSrc; // used when tracking disabled
char dsplyTimoutVal; // seconds counter for VFD/OSD dsply timeout
char frntPnlSts; // Off, On, or Timeout
char frntPnlBrit; // Dim, Med or High
char menuBkgrnd;
The Contents of Non-Volatile Memory Request command causes the Target unit to
transmit, in the response, the contents of its non-volatile memory. Two values are included
in the data segment of the command: an “Offset” data word that determines how many bytes
from the beginning of the Non-Volatile memory structure that the desired data begins, and a
“Length” data word that determines the total number of bytes to be transmitted back to the
Source unit.
NOTE: sending a “Length” data word value of zero will cause the Target unit to respond
with the rest of the structure (from offset to the end) - the number of bytes returned in the
response will reflect the actual number of bytes involved.

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 14 of 20
CONTENTS OF NON-VOLATILE MEMORY REQUEST
(CONT.)
Profile_st defaultProfile; // the "Current" f/x profile
char bass_eq; // bass EQ level
char hi_eq; // treble cut level
char centr_mod; // center mode
char surr_mod; // surr mode
char centr_lvl_mod; // level modifier for current center mode
char surr_lvl_mod; // level modifier for current surround mode
signed char sub_lvl_mod; // level modifier for subwoofer
Balance_st balance; // balance data
signed char lrBal; // item to be adjusted
signed char fbBal; //
Input_st Input[NUM_INPUTS];
char name[INPUT_NAME_WIDTH]; // input name
char fxMode; // index to the fx mode struct
Profile_st profile; // profile for this input
char bass_eq; // bass EQ level
char hi_eq; // treble cut level
char centr_mod; // center mode
char surr_mod; // surr mode
char centr_lvl_mod; // level modifier for current center mode
char surr_lvl_mod; // level modifier for current surround mode
signed char sub_lvl_mod; // level modifier for subwoofer
Balance_st balance; // balance data
signed char lrBal; // item to be adjusted
signed char fbBal; //
uchar audio_src;
char video_src;
char video_mode; // S-video or composite video
char input_level_left; // left input level for this input
char input_level_right; // left input level for this input
char graphics; // menu background = blue or video
uint flags;

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 15 of 20
CONTENTS OF NON-VOLATILE MEMORY REQUEST
(CONT.)
TunerPSet_st TnrPSet[NUM_PRESETS_TUNER];
int nFreq; // station frequency
char cBand; // USA_FM, USA_AM, EUR_FM, EUR_AM
char cRDS; // flag - rds auto or manual. if manual, user
// can store ID & PTY
char szID[RDS_TYPE_SIZE]; // 8 char station id
char cType; // index into RDSTypeTable string table
TunerState_st TnrState;
int nCountry;
int nCurBand;
int nCurFreq;
int nCurPreset;
int nCurFMFreq;
int nCurAMFreq;
int nCurLWFreq;
char RDSTblGapLow; // describe the 'hole' in the...
char RDSTblGapHi; // ...RDS type table
char unitID; // Signature unit ID
char pwrUpState; // describe the power-up state
uint version; // software revision level
char filler[13]; // unused at this time

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 16 of 20
WRITE SETTINGS INTO NON-VOLATILE MEMORY
This command causes the unit to write its non-volatile settings into non-volatile memory.
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
03
h
7E
h
74
h
None
See page 7

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 17 of 20
CONTENTS OF VOLATILE MEMORY REQUEST
COMMAND:
RESPONSE:
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
06
h
7E
h
75
h
See below
See page 7
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
20
h
30
h
01
h
01
h
02
h
Computed
7E
h
75
h
See below
See page 7
char bass_eq; // bass EQ level
char hi_eq; // treble cut level
char centr_mod; // center mode
char surr_mod; // surr mode
char centr_lvl_mod; // level modifier for current center mode
char surr_lvl_mod; // level modifier for current surround mode
signed char sub_lvl_mod; // level modifier for subwoofer
Balance_st balance; // balance data
signed char lrBal; // item to be adjusted
signed char fbBal; //
The Contents of Volatile Memory Request command causes the Target unit to transmit, in
the response, the contents of its volatile memory. Two values are included in the data
segment of the command: an “Offset” data word that determines how many bytes from the
beginning of the Volatile memory structure that the desired data begins, and a “Length” data
word that determines the total number of bytes to be transmitted back to the Source unit.
NOTE: sending a “Length” data word value of zero will cause the Target unit to respond
with the rest of the structure (from offset to the end) - the number of bytes returned in the
response will reflect the actual number of bytes involved.

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 18 of 20
SOFTWARE REVISION LEVEL REQUEST
COMMAND:
RESPONSE:
DB-25 DCE DB-9
1AA xProtective Ground
2TXD 3BA ITransmitted Data
3RXD 2BB OReceived Data
4RTS 7CA IRequest To Send
5CTS 8CB OClear To Send
6DSR 6CC OData Set Ready
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
30
h
20
h
01
h
01
h
01
h
Computed
7E
h
77
h
None
See page 7
Source
Device Type
Target
Device Type Target Unit ID Source Unit ID Command Modifier
Data
Length
Preamble
Byte Command Byte Data Byte(s) Checksum Byte
20
h
30
h
01
h
01
h
02
h
Computed
7E
h
77
h
See below
See page 7
The Software Revision Level Request command causes the target unit to transmit, in the
response, the revision level of its software. The response is a data word organized as
follows:
MSB Major revision level
LSB Minor revision level
Example: 0205hwould be software version 2.5

SIGNATURE BUS PROTOCOL MASTER DOCUMENT
Revised 2-24-98
Page 19 of 20
7GND 5AB xSignal Ground
8CD 1CF OReceived Line Signal Detector
9-- xReserved for data set testing
10 -- xReserved for data set testing
11 xUnassigned
12 SCF OSecndry Rcvd Line Signl Detctr
13 SCB OSecondary Clear to Send
14 SBA ISecondary Transmitted Data
15 DB OTransmisn Signl Elemnt Timng
16 SBB OSecondary Received Data
17 DD O Receiver Signal Element Timing
18 xUnassigned
19 SCA ISecondary Request to Send
20 DTR 4CD IData Terminal Ready
21 CG OSignal Quality Detector
22 9 CE ORing Indicator
23 CH/CI I/O Data Signal Rate Selector
24 DA ITransmit Signal Element Timing
25 xUnassigned