Mitsubishi Electric MDT421S: Controlling the LCD monitor via RS-232C/RS-485 Remote Control

English

English-35

Controlling the LCD monitor via RS-232C/RS-485 Remote Control

This LCD monitor can be controlled by a personal computer connected with an RS-232C cable or a CAT5 cable via the CAT5 Tx 

BOX (option) and CAT5 Rx BOX (option).

Functions that can be controlled by the personal computer are:

•  Power ON or OFF

•  Switching between input signals

Connection

Connection by RS-232C  (For RS-232C cable, the reverse type cable should be used.) 

Connection by CAT5 RS-485  (For CAT5 cable, the straight type cable should be used) 

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.

1)  Interface

PROTOCOL

BAUD RATE

DATA LENGTH

PARITY BIT

STOP BIT

FLOW CONTROL

RS-232C/RS-485 (CAT5)

9600 [bps]

8 [bits]

NONE

1 [bits]

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.

NOTE:

The example below shows basic commands used for the con

fi

 guration consisting of one computer and one monitor (one-to-

one connection). For commands to control multi-connected monitors, contact your dealer in advance. 

HEX

ASCII

Address code

30h 30h

‘0’ ‘0’

Function code

Function

Function

Data code

Data

Data

End code

0Dh

[Address code] 

30h 30h (In ASCII code, ‘0’ ‘0’) 

fi

 xed.

[Function code] 

A code of each 

fi

 xed control move.

[Data code] 

A code of each 

fi

 xed control data (number) and not always indicated.

[End code] 

0Dh (In ASCII code, ‘ ’ ) 

fi

 xed.

CAT5 Tx BOX

(option)

RS-232C cable

CAT5 cable

To CAT5 

OUT

To RS-232C

IN

To CAT5 

OUT

To CAT5 

RGB5 IN

To CAT5 

OUT

To CAT5 

RGB5 IN

CAT5 cable

USB cable

Type A

Type B

PC

Monitor with CAT5

Rx BOX (option)

Monitor with CAT5

Rx BOX (option)

This connection isn’t necessary when the USB COM port is used.

PC

RS-232C cable

RS-232C cable

To RS-232C OUT

To RS-232C IN

To RS-232C OUT

To RS-232C IN

Monitor

Monitor

English-36

3)  Control sequence

(1)  The command from a computer to the LCD monitor will be sent in 600 ms.

(2)  The LCD monitor will send a return command 600 ms* after it has received and encoded. If the command isn’t received 

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

(3)  The personal computer checks the command and con

fi

 rms 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)

Meaning

30 30 21 0D

‘0’ ‘0’ ‘!’ ‘      ’

30 30 21 0D

‘0’ ‘0’ ‘!’ ‘      ’

Sending commands 

from the PC

Status code from 

LCD monitor

Command for

POWER ON

Command received

(Command echoed back)

4)  Operation commands

The operation commands execute the basic operation setting of this LCD monitor.

It may not operate when changing the signal:

Operation

ASCII

HEX

POWER ON

!

21h

POWER OFF

"

22h

INPUT RGB 1

_r1

5Fh  72h  31h

INPUT RGB 2

_r2

5Fh  72h  32h

INPUT RGB 3

_r3

5Fh  72h  33h

INPUT RGB 4

_r4

5Fh  72h  34h

INPUT VIDEO

_v1

5Fh  76h  31h

INPUT DVD/HD

_v2

5Fh  76h  32h

INPUT S-VIDEO** _v3

5Fh  76h  33h

INPUT RGB 5*

_r5

5Fh  72h  35h

INPUT RGB 6

_r6

5Fh  72h  36h

• POWER OFF command should be operated over 1 minute after 

the power is turned on.

• POWER ON command should be operated over 1 minute after 

the power is turned off.

* RGB 5 becomes usable when the optional CAT5 Rx BOX is 

mounted. 

** S-VIDEO is SEPARATE only

5)  Read command

Host computer sends the command without Data-code to monitor.

After receiving this command, the monitor returns the command with Data-code of current status to host computer.

Example: When Host computer ask Power status of monitor, the status of monitor is powered-on.

Command from computer

30 30 76 50 0D   ‘0’‘0’‘v’‘P’[enter]

Command from Monitor

Detail of command

Ask about the power status of monitor.

30 30 76 50  31 0D    ‘0’‘0’‘v’‘P’‘1’[enter] Monitor is powered-on.

Structure of the Read-command

Function

Data (Receive)

Function

Data (Receive)

ON

vP

vP

1

76 50

31

OFF (stand by)

0

76 50

30

RGB-1 (HDMI)

vI

r1

76 49

72 31

RGB-2 (DVI-D)

vI

r2

76 49

72 32

RGB-3 (D-SUB)

vI

r3

76 49

72 33

RGB-6 (DISPLAY PORT)

RGB-4 (BNC)

vI

r6

76 49

72 36

RGB-5* (CAT5)

* : RGB-5 becomes usable when the optional CAT5 Rx BOX is mounted.  

vI

r5

76 49

72 35

vI

r4

76 49

72 34

Video

vI

v1

76 49

76 31

DVD/HD

vI

v2

76 49

76 32

S-VIDEO

vI

v3

76 49

76 33

HIGHBRIGHT

vM

vM

p1

76 4D

70 31

STANDARD

p2

76 4D

70 32

resolution

1 

˚

C

resolution

1 

˚

C

74 63 31

2B 20 32 35

74 63 32

2B 20 33 31

Input

Picture mode

Temperature

of internal

monitor

Around

Main board

Around

Power PCB

POWER

(ex.) +31

(ex.) +25

tc1

tc2

ASCII

HEX