NEC MultiSync LCD4215 Reference

External Control LCD3215/LCD4215



1. Application

This document defines the communicat ions method for control of the LCD3215/LCD4215 when using an

external controller

.

2. Connectors and wiring

Connector: D-Sub 9-pin

Cable: Cross (reversed) cable or null modem cable

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 LCD3215/LCD4215.

(1/37)

4. Communication Format

Header

Message

Check Code

Delimiter

Header

Delimiter

He

ader

Message

Check Code

Delimiter

Header

Delimiter

Header

Message

Check Code

Delimiter

Header

Delimiter

Header

M

essage

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

Reserved
'0'

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

Destinatio

'A'

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)

nd

2

byte) Reserved: Reserved for future extensions.

LCD3215/LCD4215 must be ASCII '0'(30h)

rd

3

byte) Destination: Destination equipment ID. (Receiver)

Specify a commands receiver’s address.

LCD3215/LCD4215 must be ASCII 'A' (41h).

(2/37)

4thbyte) Source: Source equipment ID. (Sender)

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

th

5

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.

th

6

-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

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

1

）

Get currentparameter

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



STX

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

OP code page OP code
Hi Lo Hi Lo

Header



Message

parameter” is as follows,

Check code Delimiter

ETX

2

）

Get Parameter reply
The monitor will reply with the status of the requested item specified by the controller
in the “Get parameter message”.

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

STX



Result

Hi

Lo Hi Lo Hi Lo Hi Lo MSB

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

OP code

page

OP code Type Max value Current Value

LSB MSB

(3/37)

ETX

LSB

Lo Hi Lo

Hi Lo Hi Lo Hi Lo

n+1

3

）

Set parameter

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

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

OP code

STX



4

）

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



5

）

Command

“Command message” format depends on each command.

Usually, this “command message” is used for some non-slider con trols and some sp ecial operati ons,
such as “Save curr ent settings”, “Get timing report”, “power contro l”, “S chedule”, etc. Refer to

page

Hi

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

Result

Hi Lo

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

OP code Set Value

MSB

OP code

page

OP code

ETX

LSB

Type Max valu e

MSB

Requested setting

Value

LSB MSB LSB

ETX

section 5. 5 “Commands message” for more details.

6

）

Command reply

The monitor replies to a query from the controller.

“Command reply message” format depends on each command.
Refer to section 5.5 “Commands message” for more details.

4.5 Check code

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

Header Message

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

Check code

Delimiter

(4/37)

D

= D1 XOR D2 XOR D3 XOR ,,, D

n+1

n

XOR: Exclusive OR

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

SOH Reserved

Destination

Address

Header Message

Source

Address

Message

type

Message length STX

OP code

page

OP code Set Value ETX

Check

code

(BCC)

Delimiter

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

D

D1 D2 D3 D4 D5 D6 D7 D

0

D

D

D

D

D

D

D

D

8

9

10

11

12

13

14

15

D

16

D18

17

Check code (BCC) D

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

17

= 3 0h xor 41h xor 30h xor 45h xor 30h xor 41h
xor 02h xor 30h xo r 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).

(5/37)

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

th

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

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

st

1

byte) STX : Start of Message

ASCII STX (02h)

nd-3rd

2

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 page (Hi) = ASCII '0' (30h)
OP code page (Lo) = ASCII '2' (32h)



“Appendix



STX

st

1

Refer to Operation code table. (Appendix A)

th–5th

4

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.

th

6

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

th

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

LSB MSB

LSB

LCD3215/LCD4215 replies with a current value and the status of the reques ted item (operati on code).

st

1

byte) STX : Start of Message

ETX

ASCII STX (02h)

nd-3rd

2

bytes) Result code.

(6/37)

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

00h: No Error.
01h: Unsupported oper ation with this monitor or unsupported operation under current condition.

This resul t 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

4

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 codes table.

th

6

–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).

th

8

-9thbytes) Type: Operation type code
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).

00h: Set parameter

01h: Momentary

Like the AutoSetup function which automatically changes the parameter.

th

10

-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)

th

14

-17thbytes) Current Value: (16bits)

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

th

18

byte) ETX: End of Message

ASCII ETX (03h)

5.3 Set parameter

th

STX

st

1

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.

st

1

byte) STX: Start of Message

ASCII STX (02h)

nd-3rd

2

bytes) OP code page: Operation code page

(7/37)

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

4

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

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

Refer to the Operation code table.

th-9th

6

bytes) Set value

: (

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

th

10

byte) ETX: End of Message

st

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

nd

2

= ASCII '1' (31h)

rd

3

= ASCII '2' (32h)

th

4

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

ASCII ETX (03h)

STX

st

1

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.

st

1

byte) STX: Start of Message

ASCII STX (02h)

nd-3rd

2

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

4

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

6

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

Requested setting

Value

LSB

ETX

th

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

8

bytes) Type: Operation type code

(8/37)

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

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

th

10

-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)

th

14

-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)

th

18

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

(9/37)

Bit 5-2 Reserved (Don't care )
Bit 1 1:Positive Horizontal sync polar ity.
0:Negative Horizonta l sync polarity.
Bit 0 1:Positive Vertical sy nc polarit y.





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 controller 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'-'A '-'0'-'C'-'0'-'6' STX-'0'-'0 '-'1'-'0'-ETX BCC CR

Header

SOH (01h): Start Of Header
'0' (30h): Reserved
'A' (41h): Monitor ID

LCD3215/LCD4215 must be ASCII 'A' (41h).
'0' (30h): Message sender is the controller
'C' (43h): Message 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.

(10/37)

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'-'A'-'D'-'1'-'2' STX-'0'-'0'-'0'-'0'-'1'-'0'-'0'-'0'

-'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
'A' (41h): Monitor ID

LCD3215/LCD4215 must be ASCII 'A' (41h).
'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) as 50
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

SOH-'0'-'A'-'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
'A' (41h): Monitor ID

LCD3215/LCD4215 must be ASCII 'A' (41h).
'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) as 80
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.

BCC CR

Check

code

%

Delimiter

%

Delimiter

(11/37)

Header Message Check code

SOH-'0'-'0'-'A'-'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
'A' (41h): Monitor ID

LCD3215/LCD4215 must be ASCII 'A' (41h).

'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) as 80
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'-'A'-'0'-'A'-'0'-'4' STX-'0-'C'-ETX BCC CR

Header
SOH (01h): Start Of Header
'0' (30h): Reserved
'A' (41h): Monitor ID

LCD3215/LCD4215 must be ASCII 'A' (41h).
'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.

LCD3215/LCD4215 has two built-in temperature 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

%

(12/37)