Command Format And Answer Format - Denon DN-C635 Service Manual

Revision1.0
Date 2003-01-28
2

Command format and answer format

The DN-C635 uses commands each of which consists of a data row (some commands no need PC)
composed of command codes (CC) and parameter codes (PC). The host shall be designed to send block
check characters (BCC) following ETX, with the data row enclosed in STX (text start: 0x02) and ETX (text
termination: 0x03). The DN-C635 shall complete command receive with correct BCC codes.
Here are the formats.
Commands <STX> <CC> <PC0> <PC1> <PC2> <...........> <PCn> <ETX> <BCCH><BCCL>
STX (Start of TeXt)
CC (Command Code)
PC (Parameter Code)
ETX (End of TeXt)
BCC (Block Check Character)
BCCH is an ASCII code converted from X (higher 4 bits of sum) and BCCL is converted from Y (lower 4 bit of
sum).
BCCH and BCCL are ASCII coded data.
Answers<STX> <RC> <AC> <PC0> <PC1> <PC2> <> <PCn> <ETX><BCCH><BCCL>
STX (Start of TeXt)
RC (Reply Code)
AC (Answer Code)
PC (Parameter Code)
ETX (End of TeXt)
BCC (Block Check Character)
BCCH is an ASCII code converted from X (higher 4 bits of sum) and BCCL is converted from Y (lower 4 bit of
sum).
BCCH and BCCL are ASCII coded data.
For BCC;
1) Add from command through STX.
2) Take two lowest digits in BCC sum. ("tens" & "ones" place)
3) Convert tens & ones place numbers in to hex.
Examples:
0x02
Command code
Numbers of parameters are defined for each command.
0x03
CC + PC0 + PC1 + PC2 + + PCn + ETX = XY (hex)
Each of X and Y is 4 bit long, X, Y=0,1,2,3,4,5,6,7,8,9,A, B, C, D, E, F
0x02
Reply code (=Command code)
Answer code
Numbers of parameters are defined for each command.
0x03
RC+AC + PC0 + PC1 + PC2 + + PCn + ETX = XY (hex)
Each of X and Y is 4 bit long, X, Y=0,1,2,3,4,5,6,7,8,9,A, B, C, D, E, F
BCC=337 BCCH=33, BCCL=37 (discard hundredths place 3)
BCC=107 BCCH=30, BCCL=37 (discard hundredths place 1)
BCC= 45 BCCH=34, BCCL=35 (convert directly)
BCC= AC BCCH=41, BCCL=43 (convert directly)
DN-C635 Serial Interface Specification
6 page of 39