NEC LCD4020, LCD4620 user manual Connection, English-32

Controlling the LCD monitor via RS-232C Remote Control

This LCD monitor can be controlled by connecting a personal computer with a RS-232C terminal.

Functions that can be controlled by a personal computer are:

¥Power ON or OFF

¥Switching between input signals

Connection

LCD Monitor + PC MultiSync MultiSync

PC	IN	OUT	RS-232C (IN)	RS-232C (OUT)	RS-232C (IN)
(Out)

RS-232C Cable RS-232C Cable

RS-232C (OUT)

MultiSync

NOTE: If your PC (IBM or IBM compatible) is equipped only with a 25-pin serial port connector, a 25-pin serial port adapter is required. Contact your dealer for details.

*In order to function, the RS-232C OUT terminal can only be connected to another monitor of the same model. Do not connect to other types of equipment.

The following control sequence is used for a single LCD4020/LCD4620. To control multiple LCD4020/LCD4620 monitors that are daisy-chained together please use the extended control command. Instructions for the extended control command can be found on the CD included with the display. The file is called ÒExternal_control_LCD4X20.pdfÓ. When using the following control commands, all of the daisy-chained monitors can be controlled at the same time from one monitor. Reply and status commands, however, will only pertain to the primary monitor, not secondary monitors.

1) Interface

PROTOCOL	RS-232C
BAUD RATE	9600 [bps]
DATA LENGTH	8 [bits]
PARITY BIT	NONE
STOP BIT	1 [bits]
FLOW CONTROL	NONE

This LCD monitor uses RXD, TXD and GND lines for RS-232C control.

2)Control command diagram

The command is structured by the address code, function code, data code and end code. The length of the command is different for each function.

	Address code	Function code	Data code		End code
HEX	30h 30h	Function	Data		0Dh
ASCII	'0' '0'	Function	Data
	[Address code]	30h 30h (ASCII code, '0' '0'), fixed.
	[Function code]	A code of each fixed control move.
	[Data code]	A code of each fixed control data (number) and not always indicated.
	[End code]	0Dh (In ASCII code, '		') fixed.

English-32