Hitachi 42EDT41A Service Manual page 13

Plasma TV
3.2- Command Summary (Sending and Receiving Data)
3.2.1- Data received by Television
TV will accept data from the PC when it is properly formatted as shown in table 3.2.1.1 only
•
when the Terminal Mode is ON.
• The command length is 12 bytes with a start and stop byte. Therefore total command strings
are 14 bytes
The command consists of 6 Hex codes from 1
•
All command strings should be described in character code and then converted to Hex Code.
•
Table 3.2.1.2 shows the 3 types of command formats
•
All commands are classified into these 3 types of command by the 1
•
Table 3.2.1.1 Communication format received by Television
Start
Received byte # 1 2
Contents Start
Of Function
Commands
Character -Hex STX
0~F
Code- Hex *1
02
*1 Character Code: "0"-"9" → 30-39, "A" –"F" →41-46
Note- See code conversion examples in section 4 for conversion details.
Table 3.2.1.2 Format of Commands Received by Television (12 bytes)
Form No. Action
Reset
(a)
Write/Read
(b) Read Data
(c) Write Data
3.2.2 Format of commands sent from television to PC
• Upon completion of a command sent to the television as shown in table 3.2.1.2, The
television will respond with an answer as shown in table 3.2.2.
• In the event that a command is rejected by the television, an Hex 15 will be sent to the PC.
Sent byte No.
Contents of the
command
Character (Hex)
Code (Hex)
*1 Character Code: Example "0"-"9" → "30"-"39" , "A-F → 41- 46
st
3 4 5 6
st nd rd
1 2 3
R/W Upper byte
(Function)
0~F 0~F 0~F 0~F
*1 *1 *1 *1
st
1
Command
(**)
Command
(**)
Command
(**)
Table 3.2.2 Answer format from television to PC
Communication
Normal/Error
1
Accepted or
Rejected
ACK/NAK
06/15
th
to 6 as shown below. (Total 12 bytes)
st
and 2
7 8 9 10 11
th th
4 5
Lower byte Upper byte
(Function) (Data)
0~F 0~F 0~F 0~F 0~F
*1 *1 *1 *1 *1
Command (12 byte)
nd rd th
2 3 4
Dummy Dummy Dummy
(00) (00) (00)
Operation Command Command
(**) (**) (**)
Operation Command Command
(**) (**) (**)
When requesting read data only from the TV
To the PC, the following format applies
1 2 3
Data
Start
Upper byte
STX 0~F 0~F
02 *1
13
Revision 1.0
nd
command byte.
Stop
12 13 14
6th Stop
Lower byte
(Data)
ETX
0~F 0~F
*1 *1 03
th th
5 6
Dummy Dummy
(00) (00)
Dummy Dummy
(00) (00)
Data Data
(**) (**)
4 5 6
Data
Stop
Lower byte
0~F 0~F ETX
*1 03
PW1A