NEC M40-2-AV User Manual

External Control NEC LCD Monitor

1. Application

This d ocument defines the communications method for control of the NEC LCD monitor, MultiSync

LCD4020/46 20/5220/6520 and MULTEOS M40/46 when using an external controller

2. Connectors and wiring

Connector: D-Sub 9-pin

Cable: Cross (reversed) cable or null modem cable

(Please refer “Using the LCD with RS-232C” on each User’s manual.)

3. Communication Parameter

(1) Communication system Asynchronous

(2) Interface RS-232C

(3) Baud rate 9600bps (4) Data length 8bits (5) Parity None (6) Stop bit 1 bit (7) Communication code ASCII

3.1 Communication timing

The controller should wait for a packet interval before next command is sent. The packet interval needs to be longer than 600msec for the LCD monitor.

(1/40)

4. Communication Format

Header

Message

Check Code

Delimiter

Header

Del

imiter

Header

Message

Check Code

Delimiter

Header

Delimiter

Header

Message

Check Code

Delimiter

Header

Delimiter

Header

Message

Check Code

Delimiter

Header Message Check Code Delimiter

The command packet consists of four parts, Header, Message, Check code and Delimiter.

Sequence of a typical procedure to control a monitor is as follows,

[A controller and a monitor, two-way communication composition figure]

Get Parameter

Get Parameter Reply

Message

Check Code

Set Parameter

Set Parameter Reply

Message

Check Code

Get Parameter

Get Parameter Reply

Message

Check Code

Save Current Setting Command

4.1 Header block format (fixed length)

SOH

1st 2nd 3rd 4th 5th 6th -7th

Reserved '0'

Destination Source

Header

Message Type

Monitor Controller

The controller send s command to get a value from the monitor that you want to change.

The monitor replies a current value of the requested item.

The controller sends commands to set an adjusted value.

The monitor replies to the controller for confirmation.

The controller sends command to get a value for confirmation.

The monitor replies an adjusted value.

The controller requests to store the adjusted value to the monitor.

Message Check code Delimiter

Message Length

1stbyte) SOH: Start of Header

ASCII SOH (01h)

byte) Reserved: Reserved for future extensions.

On this monitor, it must be ASCII '0'(30h).

byte) Destination: Destination equipment ID. (Receiver)

Specify a commands receiver’s address.

This value must match the “Monitor ID No.” set in the OSD.

(2/40)

“Monitor ID” to “Destination Address” conversion table is as follows,

Monitor ID Destination

Address (ASCII)

Monitor ID Destination

Address (ASCII)

1 ‘A’(41h) 14 ‘N’(4Eh) 2 ‘B’(42h) 15 ‘O’(4Fh) 3 ‘C’(43h) 16 ‘P’(50h) 4 ‘D’(44h) 17 ‘Q’(51h) 5 ‘E’(45h) 18 ‘R’(52h) 6 ‘F’(46h) 19 ‘S’(53h) 7 ‘G’(47h) 20 ‘T’(54h) 8 ‘H’(48h) 21 ‘U’(55h) 9 ‘I’(49h) 22 ‘V’(56h) 10 ‘J’(4Ah) 23 ‘W’(57h) 11 ‘K’(4Bh) 24 ‘X’(58h) 12 ‘L’(4Ch) 25 ‘Y’(59h) 13 ‘M’(4Dh) 26 ‘Z’(5Ah) ALL ‘*’(2Ah)

Ex.) If you want to control a monitor that has the "ID No." as '1', specify a destination address

'A'(41h). If you want to control all of the monitors which are connected by a daisy chain, specify

a destination address ‘

＊

’(2Ah).

byte) Source: Source equipment ID. (Sender)

Specify a sender address. The controller must be ‘0’ (30h).

byte) Message Type: (Case sensitive.)

Refer to section 4.2 “Message block format” for more details. ASCII 'A' (41h): Command.

ASCII 'B' (42h): Command reply. ASCII 'C' (43h): Get current parameter from a monitor.

ASCII 'D' (44h): "Get parameter" reply. ASCII 'E' (45h): Set parameter.

ASCII 'F' (46h): "Set parameter" reply.

-7th bytes) Message Length: Specify the length of the message (that follows the header) from STX to ETX.

This length includes STX and ETX. The byte data must be encoded to ASCII characters.

Ex.) The byte data 3Ah must be encoded to ASCII characters '3' and 'A' (33h and 41h).



The byte data 0Bh must be encoded to ASCII characters '0' and 'B' (30h and 42h).

4.2 Message block format

Header

Message

Check code Delimiter

“Message block format” is allied to the “Message Type” in the “Header”. Refer to the section 6 “Message format” for more detail.

(3/40)

1）Get currentparameter

Lo Hi Lo

Hi Lo Hi Lo Hi Lo

The controller sends this message when you want to get the status of the monitor. For the status that you want to get, specify the “OP code page” and “OP code”,

refer to “Appendix A. Operation code table”.

“Message format” of the “Get current



）

Get Parameter reply

The monitor will reply with the status of the requested item specified by the controller

in the “Get parameter message”.

STX



）

Set parameter

The controller sends this message to change a setting of the monitor.

STX



STX

Refer to section 5.1 “Get current parameter from a monitor.” for more details.

“Message format” of the “Get parameter reply” is as follows,

Result

Lo Hi Lo Hi Lo Hi Lo MSB

Refer to section 5.2 “Get parameter reply” for more details.

Message format of the “Set parameter” is as follows,

OP code

page

Refer to section 5.3 “Set parameter” for more details.

OP code page Hi Lo Hi Lo

OP code

page

OP code Set Value

OP code Type Max value Current Value



parameter” is as follows,

OP code

MSB

ETX

LSB

ETX

LSB MSB

ETX

LSB

）

Set Parameter reply

The monitor replies with this message for a confirmation of the “Set parameter message”.

Message format of the “Set parameter reply” is as follows,

STX

Result

Hi Lo



）

Command “Command message” format depends on each command. Usually, this “command message” is used for some non-sli der controls and some special o perations,

such as “Save curr ent settings”, “Get timing report”, “power cont rol”, “Schedule”, etc. Refer to section 5. 5 “Commands message” for more details.

）

Command reply The monitor replies to a query from the controller.

Refer to section 5.4 “Set parameter reply” for more details.

OP code

page

OP code

Type Max value

MSB

LSB MSB LSB

Requested setting

Value

ETX

(4/40)

“Command reply message” format depends on each command.

n+1

Refer to section 5.5 “Commands message” for more details.

4.5 Check code

Header Message

Check code is the Block Check Code (BCC) between the Header and the End of Message except SOH.

27 26 25 24 23 22 21 20 SOH D0 Reserved D1 Destinatio n D2 Source D3 Type D4 Length D5 STX D6 Data D7 | | | | ETX Dn Check code D

P P P P P P P P

= D1 XOR D2 XOR D3 XOR ,,, D

n+1

XOR: Exclusive OR

Check code

Delimiter

Following is an example of a Check code (BCC) calculation.

Header Message

SOH Reserved

01 30 41 30 45 30 41 02 30 30 31 30 30 30 36 34 03 77 0D

Destination

Address

D1 D2 D3 D4 D5 D6 D7 D

Source

Address

Message

type

Message length STX

OP code

page

OP code Set Value ETX

Check

Delimiter

code

(BCC)

D18

Check code (BCC) D

= D1 xor D2 xor D3 xor … xor D14 xor D15 xor D16

= 3 0h xor 41h xor 30h xor 45h xor 30h xor 41h

xor 02h xor 30h xor 30h xor 31h xor 30h xor 30h xor 30h xor 36h xor 34h xor 03h

= 77h

4.6 Delimiter

Header Message Check code

Delimiter

Packet delimite r code; ASCII CR(0Dh).

(5/40)

5. Message type

5.1 Get current Parameter from a monitor.

STX

OP code page Hi Lo Hi Lo

1st 2nd-3rd 4th–5th 6

OP code

ETX

Send this message when you want to get the status of a monitor.

For the status that you want to get, specify the “OP co de page” the “OP co de”, refer to A. Operati on code table”.

byte) STX : Start of Message

ASCII STX (02h)

nd-3rd

bytes) OP code page: Operation code page.

Specify the “OP code page” for the control which you want to get the status. Refer to “Appendix A Operation code table” for each item.

OP code page data must be encoded to ASCII characters. Ex.) The byte data 02h must be encoded to ASCII characters '0' and '2' (30h

and 32h).

OP code page 02h -> OP code pa ge (Hi) = ASCII '0' (30h) OP code page (Lo) = ASCII '2' (32h)



“Appendix



STX

Refer to Operation code table. (Appendix A)

th–5th

bytes) OP code: Operation code

Refer to “Appendix A Operation code table” for each item. OP code data must be encoded to ASCII characters.

Ex.) The byte data 3Ah must be encoded to ASCII characters '3' and 'A' (33h and 41h). OP code 3Ah -> OP code (Hi) = ASCII '3' (33h)

OP code (Lo) = ASCII 'A' (41h) Refer to Operation code table.

byte) ETX: End of Message

ASCII ETX (03h)

5.2 "Get parameter" reply

Result OP code page OP code

Hi Lo Hi Lo Hi Lo Hi Lo MSB

2nd-3rd 4th–5th 6th –7th 8th -9

Type Max value Current Value

10th -13th 14th -17th 18th

LSB MSB

LSB

The monitor replies with a current value and the status of the requested item (operation code).

byte) STX: Start of Message

ETX

ASCII STX (02h)

nd-3rd

bytes) Result code.

(6/40)

These bytes indicate a result of the requested commands as follows,

00h: No Error. 01h: Unsupporte d operation with this moni tor or unsupported operation under current condition.

This result code from the monitor is encoded to ASCII characters. Ex.) The byte data 01h is encoded to ASCII character '0' and '1' (30h and 31h).

th–5th

bytes) OP code page: Operation code page. These bytes indicate a replying item's OP code page.

This returned value from the monitor is encoded to ASCII characters. Ex.) The byte data 02h is encoded to ASCII character '0' and '2' (30h and 32h).

Refer to the operation code table.

–7thbytes) OP code: Operation code

These bytes indicate a replying item's OP code. This returned value from the monitor is encoded to ASCII characters.

Refer to the operation code table. Ex.) The byte data 1Ah is encoded to ASCII character '1' and 'A' (31h and 41h).

-9thbytes) Type: Operation type code 00h: Set parameter

01h: Momentary Like the Auto Setup function which automatically changes the parameter.

This returned value from the monitor is encoded to ASCII characters. Ex.) The byte data 01h is encoded to ASCII character '0' and '1' (30h and 31h).

-13thbytes) Max. value: Maximum value which monitor can accept. (16bits) This returned value from the monitor is encoded to ASCII characters.

Ex.) '0','1','2' and '3' means 0123h (291)

-17thbytes) Current Value: (16bits)

This returned value from the monitor is encoded to ASCII characters. Ex.) '0','1','2' and '3' means 0123h (291)

byte) ETX: End of Message

ASCII ETX (03h)

5.3 Set parameter

STX

OP code page

OP code

Hi Lo Hi Lo MSB

Set Value

LSB

2nd-3rd 4th-5th 6th-9th 10

ETX

Send this message to change monitor’s adjustment and so on.

The controller requests a monitor to change value.

byte) STX: Start of Message

ASCII STX (02h)

nd-3rd

bytes) OP code page: Operation code page

(7/40)

This OP code page data must be encoded to ASCII characters.

Hi Lo Hi

Ex.) The byte data 02h must be encoded to ASCII '0' and '2' (30h and 32h). Refer to the Operation code table.

th-5th

bytes) OP code: Operation code This OP code data must be encoded to ASCII characters.

Ex.) OP code 1Ah -> OP code (Hi) = ASCII '1' (31h) OP code (Lo) = ASCII 'A' (41h)

Refer to the Operation code table.

th-9th

bytes) Set value

: (

16bit) This data must be encoded to ASCII characters. Ex.) 0123h -> 1

2 3

byte) ETX: End of Message

(MSB) = ASCII '0' (30h)

= ASCII '1 ' (31h)

= ASCII '2 ' (32h)

(LSB) = ASCII '3 ' (33h)

ASCII ETX (03h)

STX

5.4 "Set parameter" reply

Result OP code page

Lo Hi Lo Hi Lo MSB

OP code

Type Max value

LSB MSB

2nd-3rd 4th-5th 6th-7th 8th-9th 10th-13th 14th -17th 18

The Monitor echoes back the parameter and status of the requested operation code.

byte) STX: Start of Message

ASCII STX (02h)

nd-3rd

bytes) Result code

ASCII '0''0' (30h, 30h): No Error. ASCII '0''1' (30h, 31h): Unsupported operation with this monitor or unsupported operation under

current condition.

th-5th

bytes) OP code page: Echoes back the Operation code page for confirmation.

Reply data from the monitor is encoded to ASCII characters. Ex.) OP code page 02h -> OP code page = ASCII '0' and '2' (30h and 32h)

Refer to Operation code table.

th-7th

bytes) OP code: Echoes back the Operation code for confirmation.

Requested setting

Value

LSB

ETX

Reply data from the monitor is encoded to ASCII characters. Ex.) OP code 1Ah -> OP code (Hi) = ASCII '1' (31h)

OP code (Lo) = ASCII 'A' (41h) Refer to Operation code table

th-9th

bytes) Type: Operation type code

(8/40)

ASCII '0''0' (30h, 30h): Set parameter

ASCII '0''1' (30h, 31h): Momentary Like Auto Setup function, that automatically changes the parameter.

-13thbytes) Max. value: Maximum value that monitor can accept. (16bits) Reply data from the monitor is encoded to ASCII characters.

Ex.) '0''1''2''3' means 0123h (291)

-17thbytes) Requested setting Value: Echoes back the parameter for confirmation. (16bits)

Reply data from the monitor is encoded to ASCII characters. Ex.) '0''1''2''3' means 0123h (291)

byte) ETX: End of Message ASCII ETX (03h)

5.5 Commands

"Command message format" depends on each command

Some commands are shown with usage. Refer to

section 7 to 10.

5.5.1 Save Current Settings.

The controller requests for the monitor to store the adjusted value.

STX



Command code '0' 'C'

ETX

Send "OC"(30h, 43h) as Save current settings command. Complete "Save Current setting" command packet as follows;

ASCII: 01h-30h-41h-30h-41h-30h-34h-02h-30h-43h-03h-CHK-0Dh

SOH-'0'-'A'-'0'-'A'-'0'-'4'-STX-'0'-'C'-ETX-CHK- CR

The monitor replies the packet for confirmation as follows;

SOH-'0'-'0'-'A'-'B'-'0'-'6'-STX-'0'-'0'-'0'-'C'-ETX-CHK- CR

5.5.2 Get Timing Report and Timing reply.

The controller requests the monitor to report the displayed image timing.

STX

Command code '0' '7'

ETX



Send "07"(30h, 37h) as Get Timing Report command.

Complete "Get Timing Report" command packet as follows;

ASCII: 01h-30h-41h-30h-41h-30h-34h-02h-30h-37h-03h-CHK-0Dh

SOH-'0'-'A'-'0'-'A'-'0'-'4'-STX-'0'-'7'-ETX-CHK- CR

The monitor replies status as the following format;

Command SS H Freq. V Freq.

'4' 'E' Hi Lo MSB LSB MSB LSB

SS: Timing status byte

ETX



STX

Bit 7 = 1: Sync Frequency is out of range. Bit 6 = 1: Unstable count

(9/40)

Bit 5-2 Reserved (Don't care) Bit 1 1:Po sitive Horizontal sync polarity. 0:Negative Horizonta l sync pol arity. Bit 0 1:Po sitive Vertical sync polarity.



H Freq: Horizontal Frequency in unit 0.01kHz

V Freq: Vertical Frequency in unit 0.01Hz

Ex.) When H Freq is '1''2''A''9' (31h, 32h, 41h, 39h), it means 47.77kHz.

5.5.3 NULL Message

0:Negative Vertical sync polarity.

STX

The NULL message returned from the monitor is used in the following cases;



01h-30h-30h-41h-41h-30h-34h—02h-42h-45h-03h-CHK-0Dh

SOH-'0'-'0'-'A'-'A'-'0'-'4'-STX-'B'-'E'-ETX-CHK- CR

Command code 'B' 'E'

A timeout error has occurred. (The default timeout is 10sec.)

The monitor receives an unsupported message type. The monitor detects a packet BCC (Block Check Code) error.

To tell the controlle r that th e monitor does not have any answer to give to the host ( not ready or n ot expected)

Complete " NULL Message" command packet as follows;

ETX

6. Typical procedure example

The following is a sample of procedures to control the monitor, these are examples of "Get parameter",

"Set parameter" and "Save current settings".

6.1. How to change the “Brightness” setting.

Step 1. The controller requests the Monitor to reply with the current brightness setting and capability

to support this operation. (Get parameter)

Header Message Chec k code Delimiter

SOH-'0'-Mo nitor ID-'0'-'C'-'0'-'6' STX-'0'-'0 '-'1'-'0'-ETX BCC CR

Header

SOH (01h): Start Of Header '0' (30h): Reserved Monitor ID: Specify the Monitor ID from which you want to get a value.

Ex.) If Monitor ID is '1', specify 'A'. '0' (30h): Message sender is the controller. 'C' (43h): Message type is "Get parameter command". '0'-'6' (30h, 36h): Message length is 6 bytes.

Message

STX (02h): Start of Message '0'-'0' (30h, 30h): Operation code page number is 0. '1'-'0' (31h, 30h): Operation code is 10h (in the OP code page 0). ETX (03h): End of Message

Check code

BCC: Block Check Code Refer to th e section 4.5 “Check code” for a BCC calculation.

(10/40)

Delimiter

CR (0Dh): End of packet

Step 2. The monitor replies with current Brightness setting and capability to support this operation.

Header Message Check code

SOH-'0'-'0'-Monitor ID-'D'-'1'-'2' STX-'0'-'0'-'0'-'0'-'1'-'0'-'0'-'0'

BCC CR

-'0'-'0'-'6'-'4'-'0'-'0'-'3'-'2'-ETX

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'. 'D' (44h): Message Type is "Get parameter reply". '1'-'2' (31h, 32h): Message length is 18 bytes.

Message

STX (02h): Start of Message

'0'-'0' (30h, 30h): Result code. No error. '0'-'0' (3 0h, 30h): Operation code page number is 0. '1'-'0' (31h, 30h): Operation code is 10h (in the page 0). '0'-'0' (30h, 30h): This operation is "Set parameter" type. '0'-'0'-'6'-'4' (30h, 30h, 36h, 34h): Brightness max value is 100(0064h). '0'-'0'-'3'-'2' (30h, 30h, 33h, 32h): Current Brightness setting is 50(0032h) . ETX (03h): End of Message

Check code

BCC: Block Check Code Refer to th e section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet

Step 3. The controller request the monitor to change the Brightness setting

Header Message

Check

code

SOH-'0'-Monitor ID-'0'-'E'-'0'-'A' STX-'0'-'0'-'1'-'0'-'0'-'0'-'5'-'0'-ETX BCC CR

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 . 'E' (45h): Message Type is "Set parameter command". '0'-'A' (30h, 41h): Message length is 10 bytes.

Message

STX (02h): Start of Message

'0'-'0' (30h, 30h): Operation code page number is 0. '1'-'0' (31h, 30h): Operation code is 10h (in the page 0). '0'-'0'-'5'-'0' (30h, 30h, 35h, 30h): Set Brightness setting 80(0050h). ETX (03h): End of Message

Check code

BCC: Block Check Code Refer to th e section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet

Step 4. The monitor replies with a message for confirmation.

Delimiter

(11/40)

Header Message Check code

SOH-'0'-'0'- Monitor ID -'F'-'1'-'2' STX-'0'-'0'-'0'-'0'-'1'-'0'—'0'-'0'-'0'

-'0'-'6'-'4'-'0'-'0'-'5'-'0'-ETX

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'.

'F' (46h): Message Type is "Set parameter reply".

'1'-'2' (31h, 32h): Message length is 18 bytes.

Message

STX (02h): Start of Message

'0'-'0' (30h, 30h): Result code. No error. '0'-'0' (3 0h, 30h): Operation code page number is 0. '1'-'0' (31h, 30h): Operation code is 10h (in the page 0). '0'-'0' (30h, 30h): This operation is "Set parameter" type. '0'-'0'-'6'-'4' (30h, 30h, 36h, 34h): Brightness max value is 100(0064h). '0'-'0'-'5'-'0' (30h, 30h, 35h, 30h): Received a Brightness setting was 80(0050h) . ETX (03h): End of Message

Check code

BCC: Block Check Code Refer to th e section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet



Repeat Step 1 and Step 2, if you need to check the Brightness setting. (Recommended)

Step 5. Request the monitor to store the Brightness setting. (Save Current Settings Command)

Header Message Check code

SOH-'0'-Monitor ID-'0'-'A'-'0'-'4' STX-'0-'C'-ETX BCC CR

Header

SOH (01h): Start Of Header '0' (30h): Reserved Monitor ID: Specify the Monitor ID which you want to store the setting.

Ex.) If Monitor ID is '1', specify 'A'. '0' (30h): Message sender is the controller. 'A' (41h): Message type is "Command". '0'-'4' (30h, 34h): Message length is 4 bytes.

Message

STX (02h): Start of Message '0'-'C' (30h, 43h): Command code is 0Ch as "Save current settings". ETX (03h): End of Message

Check code

BCC: Block Check Code Refer to th e section 4.5 “Check code” for a BCC calculation.

Delimiter

CR (0Dh): End of packet

Delimiter

BCC CR

6.2. How to read the measurement value of the built-in temperature sensors.

MultiSync LCD4020/4620/5220/6520 has three, or MULTEOS M40/46 has two built-in temperat ure sensors. The controller can monitor inside temperatures by using those sensors through RS-232C.

The following shows the procedure for reading the temperatures from the sensors.

Step 1. Select a temperature sensor which you want to read.

Delimiter

Header Message

SOH-'0'-Monitor ID-'0'-'E'-'0'-'A' STX-'0'-'2'-'7'-'8'-'0'-'0'-'0'-'1'-ETX BCC CR

(12/40)

Check

code

Delimiter

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NEC M40-2-AV User Manual

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