MD-119 HW Manual
Display UART Command
C-3
CMD (Message Commands and Queries)
The command can be one of the following values:
CMD 0
CMD 1
CMD 2
ASCII
Description
0x42
0x4C
0x49
“BLI”
Brightness Control
0x45
0x54
0x43
“ETC”
Elapsed Time Counter Query
0x44
0x53
0x54
“DST”
Display State
0x4D
0x41
0x4E
“MAN”
Manufacturer ID Code
0x4D
0x43
0x43
“MCC”
OSD Control
0x50
0x4F
0x54
“POT”
Potentiometer Control
0x53
0x4E
0x42
“SNB”
Serial Number Query
0x53
0x57
0x49
“SWI”
Software Version Query
0x54
0x59
0x50
“TYP”
Type/Model Number Query
0x56
0x45
0x52
“VER”
ID Version Number Query
LEN (Data Length)
This byte defines the length of data in the message in bytes. The maximal value for this field is 74 bytes, and
the minimal value is 0 byte.
IHCHK (Inverse Header Checksum)
This is a simple 8-bit checksum of the header data, message bytes 0 to 5 on which a bit-wise inversion has been
performed. The checksum should be initialized to 0. The 8-bit sum (without carry) of bytes 0, 1, 2, 3, 4, 5, and
6 shall be 0xFF.
If a message is received with an incorrect checksum, the display will replay with the attention code set to NAK
and no data field. This does not apply to Broadcast messages in RS-485 mode, in which case there will be no
reply.
DATA (Data Field)
The data field shall only be transmitted if LEN is larger than 0. This field depends on the CMD transmitted.
IDCHK (Inverse Data Checksum)
These bytes shall be only transmitted if LEN is larger than 0. This is a simple 8-bit checksum of the data field,
message bytes 7 to 7+(LEN-1) on which a bit-wise inversion has been performed. The checksum shall be
initialized to 0. The 8-bit sum (without carry) of bytes 7 through 7+LEN inclusive shall be 0xFF. The receiver will
