Security Enable Write - NEC MultiSync C431 User Manual

22.2 Security Enable Write

This command is used in order to write the setting of Security Enable.
1) The controller requests the monitor to set Security password.
Header
SOH-'0'-Monitor ID-
'0'-'A'-'1'-'C'
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.
'A' (41h): Message type is "Command".
'1'-'C'(31h,43h): Message length (28byte)
Message
STX (02h): Start of Message
'C'-'A'-'0'-'C' (43h, 41h, 30h, 43h): Security Password Command
'0'-'1' (30h, 31h): Enable Write
ENA: Enable/Disable
00h (30h, 30h): Disable
01h (30h, 31h): Enable
'0'-'0' (30h, 30h): Reserved
PWD1 – PWD16: Password data

The password data is encoded as the following procedure.
Ex.) In the case of password data "1234"
Step1: Password data is handled as character code.
Step2: The hexadecimal value of each original character is encoded as two ASCII
Step3: Password data is handled as character code once again.
Step4: The hexadecimal value of each original character is encoded as two ASCII
Result: The following data is assigned to PWD1-PWD16.
ETX (03h): End of Message
Check code
BCC: Block Check Code
Refer to the section 4.3 "Check code" for a BCC calculation.
Delimiter
CR (0Dh): End of packet
2) The monitor replies a written in result.
Header
SOH-'0'-'0'-Monitor ID-
'B'-'0'-'A'
Header
STX-'C'-'A'-'0'-'C'-'0'-'1'-
ENA-'0'-'0'-PWD1-...-PWD16-ETX
Example:
"1234" -> 31h 32h 33h 34h (ASCII)
characters representing the hex value.
Example:
31h 32h 33h 34h -> '3'-'1'-'3'-'2'-'3'-'3'-'3'-'4'
Example:
'3'-'1'-'3'-'2'-'3'-'3'-'3'-'4' -> 33h 31h 33h 32h 33h 33h 33h 34h
(ASCII)
characters representing the value.
Example:
33h 31h 33h 32h 33h 33h 33h 34h
-> '3'-'3'-'3'-'1'-'3'-'3'-'3'-'2'-'3'-'3'-'3'-'3'-'3'-'3'-'3'-'4'
33h 33h 33h 31h 33h 33h 33h 32h 33h 33h 33h 33h 33h 33h 33h 34h
STX-'C'-'B'-'0'-'C'-'0'-'1'-ST-ETX
Message
Message
(94/104)
Check code Delimiter
BCC CR
Check code
BCC
Delimiter
CR