Harman Kardon SIGNATURE 2.0 (serv.man11) User Manual / Operation Manual ▷ View online
SIGNATURE
B
US
P
ROTOCOL
M
ASTER
D
OCUMENT
Revised 2-24-98
Page 4 of 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.
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.
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.
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.
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 ??.
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
B
US
P
ROTOCOL
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ASTER
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OCUMENT
Revised 2-24-98
Page 5 of 20
P
ROTOCOL
F
ORMAT
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.
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
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.
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.
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
B
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OCUMENT
Revised 2-24-98
Page 6 of 20
The Command Modifier is a byte that distinguishes what type of command
is being sent.
HEX
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.
(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.
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.
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.
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
B
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OCUMENT
Revised 2-24-98
Page 7 of 20
E
XAMPLE OF
M
ESSAGE
C
REATION
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)
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
30h
20h
01h
01h
01h
03h
7Eh
02h
01h
28h
