NEC RS-232C Car Video System User Manual


 
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CR (0Dh): End of packet
Step 3. The controller request the monitor to change the Backlight setting
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
Monitor ID: Specify the Monitor ID of which you want to change a setting.
Ex.) If Monitor ID is '1', specify 'A'.
'0' (30h): Message sender is the controller.
'E' (45h): Message Type is "Set parameter command".
'0'-'A' (30h, 41h): Message length is 10 bytes.
Message
STX (02h): Start of Message
'0'-'0' (30h, 30h): Operation code page number is 0.
'1'-'0' (31h, 30h): Operation code is 10h (in the page 0).
'0'-'0'-'5'-'0' (30h, 30h, 35h, 30h): Set Backlight setting 80(0050h).
ETX (03h): End of Message
Check code
BCC: Block Check Code
Refer to the section 4.5 Check code for a BCC calculation.
Delimiter
CR (0Dh): End of packet
Step 4. The monitor replies with a message for confirmation.
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
'0' (30h): Message receiver is the controller.
Monitor ID: Indicate a replying Monitor ID.
Ex.) When this byte is set to 'A', the replying Monitor ID is '1'.
'F' (46h): Message Type is "Set parameter reply".
'1'-'2' (31h, 32h): Message length is 18 bytes.
Message
STX (02h): Start of Message
'0'-'0' (30h, 30h): Result code. No error.
'0'-'0' (30h, 30h): Operation code page number is 0.
'1'-'0' (31h, 30h): Operation code is 10h (in the page 0).
'0'-'0' (30h, 30h): This operation is "Set parameter" type.
'0'-'0'-'6'-'4' (30h, 30h, 36h, 34h): Backlight max value is 100(0064h).
'0'-'0'-'5'-'0' (30h, 30h, 35h, 30h): Received a Backlight setting was 80(0050h) .
ETX (03h): End of Message
Check code
BCC: Block Check Code
Refer to the section 4.5 Check code for a BCC calculation.
Delimiter
CR (0Dh): End of packet
Repeat Step 1 and Step 2, if you need to check the Backlight setting. (Recommended)
Step 5. Request the monitor to store the Backlight setting. (Save Current Settings Command)
Header Message
Check
code
Delimiter
SOH-'0'-Monitor ID-'0'-'E'-'0'-'A'
STX-'0'-'0'-'1'-'0'-'0'-'0'-'5'-'0'-ETX
BCC CR
Header Message Check code
Delimiter
SOH-'0'-'0'- Monitor ID -'F'-'1'-'2'
STX-'0'-'0'-'0'-'0'-'1'-'0''0'-'0'-'0'
-'0'-'6'-'4'-'0'-'0'-'5'-'0'-ETX
BCC CR