Mitsubishi Electric RS232/485/LAN Serial Communication Control Manual page 42

13.2 Auto Brightness Parameter Write
Send AutoBrightness Parameters from Host( PC or Primary Monitor) to Slave (Secondary) Monitors.
1) Write Parameters from PC to Monitor.
Header
SOH-'0'-'*'-'0'-'A'-'0'-'8'
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
'*' (2Ah): Monitor ID (Use '*' as "ALL" for Broadcasting of parameter)
'0' (30h): Message sender is the controller
'A' (41h): Message type is "Command"
'0'-'8'(30h, 38h): Message length.
Message
STX (02h): Start of Message
'C' -'2' -'2' -'2' (43h,32h,32h,32h): Auto Brightness Parameter Write command
VAL: AutoBrightness setting parameter
bit0: LIGHT FROM BACK (1:Yes,0:No)
bit1: BACK WALL (1:Near,0:Far)
bit2: FRONT SENSOR (1:On,0:Off)
bit3: BACK SENSOR (1:On,0:Off)
bit4:Saturation(1:On,0:Off)
bit5:Video Detect(1:On,0:Off)
bit6-7:Not used
VAL_H: ASCII code of bit4-7of data
VAL_L: ASCII code of bit0-3 of data
Example) If Bit0 and 1 =1 and the other bits =0, (00000011)
VAL_H='0'(0x30) VAL_L='3'(0x33)
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
2) Reply from Monitor to PC.
Basically, No need reply because it is broadcasting request.
[only for reference if the write command is done with certain destination ID]
Header
SOH-'0'-'0'-'A'-'B'-'0' -'A'
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
'0' (30h): Message receiver is the controller
'A' (41h): Monitor ID
'B' (42h): Message type is "Command reply "
'0' -'A' (30h, 41h): Message length.
Message
STX (02h): Start of Message
'C'-'3'-'2' -'2' (41h, 33h, 32h,32h): Auto Brightness Parameter Write reply Command
RES: Result code('0'(30h)-'0'(30h):Normal, 、'0'(30h)-'1'(31h):Abnormal)
VAL_H-VAL_L: AutoBrightness setting parameter
ETX (03h): End of Message
Check code
BCC: Block Check Code
Refer to the section 4.5 "Check code" for a BCC calculation.
Message
STX-'C'-'2'-'2'-'2'–[VAL
_H]-[VAL_L]-ETX
Message
STX-'C'-'3'-'2'-'2'-[RES]-[RES]-[VAL_H]
-[VAL_L]–ETX
(42/56)
Check code Delimiter
BCC CR
Check code
BCC
Delimiter
CR