Harman Kardon SIG2.0 Owners Manual - Page 5

SIGNATURE BUS PROTOCOL MASTER DOCUMENT Revised 2-24-98 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. Preamble Target Byte Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) Checksum Byte 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. Preamble Byte Target Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) 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) Preamble Target Byte Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) 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. Checksum Byte Checksum Byte Preamble Target Byte Device Type Target Unit ID Source Device Type Source Unit ID Data Length Command Modifier Command Byte Data Byte(s) 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. Checksum Byte Page 5 of 20