NEC LCD Monitor Manual page 75

2) The monitor replies the result to the controller.
Header
SOH-'0'-'0'-Monitor ID-
'B'-'0'-'A'
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'.
'B' (42h): Message type is "Command reply".
'0'-'A'(30h, 41h): Message length
Message
STX (02h): Start of Message
'C'-'3'-'1'-'D' (43h, 33h, 31h, 44h): Security Lock Control reply command
ST-EN: Lock condition result data
ST: Status
'0'-'0'(30h, 30h): No error
'0'-'1'(30h, 31h): Error
EN: Enable /Disable (Current condition)
'0'-'0'(30h, 30h): Disable
'0'-'1'(30h, 31h): Enable
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
Message
STX-'C'-'3'-'1'-'D'-
ST-EN-ETX
(75/137)
Check code Delimiter
BCC CR