HARMAN KARDON RS-232
Manual de Servicio

4.4.1 Information Field Command Sequences 4.4.1.1 Command Transmission Sequence from PC to AVR Each command consists of a four-byte hex code from the table at the end of this document. To send a command, first find the hex code listed in the chart for the specific function. Convert each byte to binary, and then precede each byte with a start bit (0) and follow it with a stop bit (1). Make certain that the time for the transmission of all four bytes does not exceed 50 ms; the AVR will interpret a time gap greater than 50 ms as the start of a new command. For example, to send the �80, 70, C1, 3E� hex code sequence to issue a �Mute� command, the sequence would be as follows, including the start and stop bit after each hex code:

TOTAL STRUTCTURE FOR THE FOUR_BYTE COMMAND When building a sequence with multiple commands, remember to insert a sufficient time delay so that the total time from the start of one four-byte command to the start of next four byte command is at least 50 ms. The protocol for code transmission does not allow for �repeat� or continuous code. Thus, for commands (such as �Volume�) for which the button would be held down when using the actual remote, the specific command (e. g., �Volume Up� or �Volume Down�) must be sent individually as many times as necessary to achieve the desired effect. The commands being sent through the RS-232 link are direct mirror images of the commands and command sequences that would be used if you were pressing the remote control buttons. In cases where a main command is issued first, followed by up/down or left/right navigation to select a choice, you will need to use the specific directional command codes for the command in use. The up/down and left/right navigation commands are NOT universal for RS-232 link; it is crucial that you use the correct navigation command control.

Harman Kardon AVR Products RS-232 Code Programming Information Version 1.0 ~ 14-November-05 Page 5 of 12