Power Control Procedure; Power Status Read - NEC MultiSync V423 Manual

7. Power control procedure

7.1 Power status read

1) The controller requests the monitor to reply a current power status.
Header
SOH-'0'-Monitor ID-'0'-'A'-'0'-'6'
Header
SOH (01h): Start Of Header
'0' (30h): Reserved
Monitor ID: Specify the Monitor ID from which you want to get status.
Ex.) If Monitor ID is '1', specify 'A'.
'0' (30h): Message sender is the controller.
'A' (41h): Message Type is "Command".
'0'-'6' (30h, 36h): Message length is 6 bytes.
Message
STX (02h): Start of Message
'0'-'1'-'D'-'6': Get power status command.
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) The monitor returns with the current power status.
Header
SOH-'0'-'0'-Monitor ID-'B'-'1'-'2'
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".
'1'-'2' (31h, 32h): Message length is 18 bytes.
Message
STX(02h):Start of Message
'0'-'2' (30h, 32h): Reserved data
'0'-'0' (30h, 30h): Result code
'D'-'6'(44h, 36h): Display power mode code
'0'-'0' (30h, 30h): Parameter type code is "Set parameter".
'0'-'0'-'0'-'4' (30h, 30h, 30h, 34h): Power mode is 4 types.
'0'-'0'-'0'-'1' (30h, 30h, 30h, 31h): Current power mode
ETX (03h): End of Message
Check code
BCC: Block Check Code
Refer to the section 4.5 "Check code" for a BCC calculation.
Delimiter
STX-'0'-'1'-'D'-'6'-ETX
STX-'0'-'2'-'0'-'0'-'D'-'6'-'0'-'0'-'0'
-'0'-'0'-'4'-'0'-'0'-'0'-'1'-ETX
00: No Error.
01: Unsupported.
<Status>
0001: ON
0002: Stand-by (power save)
0003: Suspend (power save)
0004: OFF (same as IR power off)
Message Check code
BCC
Message
(36/72)
Delimiter
CR
Check code Delimiter
BCC CR