NEC LCD4000 ユーザーズマニュアル

3) Control sequence

(1) The command from a personal computer to the LCD monitor will be sent in 400ms.
(2) The LCD monitor will send a return command 400ms* after it has received an encode.  If the command isn't 

received correctly, the LCD monitor will not send the return command.

(3) The personal computer checks the command and confirms if the command which has  been sent has been  

executed or not.

(4) This LCD monitor sends various codes other than return code.  When having a control sequence by RS-232C, 

reject other codes from personal computers side.

*: The sending time of return command may delay depending on the condition (during changing of the 

input signal, etc.).

[Example] Turn the power ON ( '  ' is for  ASCII code)

4) Operation commands

The operation commands execute the basic operation setting of this LCD monitor. 
It may not operate when changing the signal:

HEX
21h
22h
5Fh  72h  31h
5Fh  72h  32h
5Fh  72h  33h
5Fh  76h  31h
5Fh  76h  32h

Operation
POWER ON
POWER OFF
INPUT RGB 1
INPUT RGB 2
INPUT RGB 3
INPUT VIDEO
INPUT DVD/HD

ASCII
!
"
_r1
_r2
_r3
_v1
_v2

Sending commands 

from the PC etc.

30 30 21 0D
'0' '0' '!' '     '

30 30 21 0D
'0' '0' '!' '     '

Status code from LCD 

monitor

Meaning

Command for POWER ON

Command received
(Command echo back)

•  POWER OFF command will not work for 1 minute after the power is turned on.
•  POWER ON command will not work for 1 minute after the power is turned off.