User manual HARMAN KARDON SIGNATURE 2.0

[. . . ] Version 2. 5: First release. Page 3 of 20 SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 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. Data is communicated at 9600 baud, 8 data bits, 1 stop bit and no parity. [. . . ] 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. Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier 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. See above list. Page 5 of 20 SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier 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. 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. Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte 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. Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte The Command Modifier is a byte that distinguishes what type of command is being sent. HEX Command Type 01 Action request 02 Action response Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte The Command byte information required by the Command byte. Provides additional is the action that is desired. Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte The Dataadditional information required by the Command byte. the Provides bytes consist of information that is required to complete Command. The Data bytes are detailed throughout the rest of this document. Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte The Checksum is a byte whose value confirms/voids the validity of a Provides additional information required by the Command byte. 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). See the page 7 for an example. Page 6 of 20 SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 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 Target Device Type = 20h Target Unit ID = 01h Source Device Type = 30h Source Unit ID = 01h Length = 03h Modifier = 01h Command = 02h Data = 01h 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' add 01h) t Checksum = 28h Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte 7Eh 20h 01h 30h 01h Page 7 of 20 03h 01h 02h 01h 28h SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 ACKNOWLEDGMENT COMMAND: Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte 7Eh Preamble Byte 20h Target Device Type 01h Target Unit ID 30h Source Device Type 01h Source Unit ID Computed 01h Command Modifier Command Data See page 7 ACKNOWLEDGE: Data Length Command Byte Data Byte(s) Checksum Byte 7Eh 30h 01h 20h 01h 02h 02h See Below None See page 7 The acknowledge Command Byte is formed by adding 80h to the received Command Byte. [. . . ] // . . . RDS type table // Signature unit ID // describe the power-up state // software revision level // unused at this time Page 15 of 20 SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 WRITE SETTINGS INTO NON-VOLATILE MEMORY Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte 7Eh 20h 01h 30h 01h 03h 01h 74h None See page 7 This command causes the unit to write its non-volatile settings into non-volatile memory. Page 16 of 20 SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 CONTENTS OF VOLATILE MEMORY REQUEST COMMAND: Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte 7Eh 20h 01h 30h 01h 06h 01h 75h See below See page 7 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. [. . . ]