NEC RS-232C 5.5.3 NULL Message

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5.5.3 NULL Message

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



To tell the controller that the monitor does not have any answer to give to the host (not

rea dy or not ex pec ted )

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Fol low ing ope rat ion s ne ed a certain time for to execute, so the monitor will return this

message when another message is received during execution.



Power ON, Power OFF, Auto Setup, Input, PIP Input, Auto Setup and Factory reset.



Complete "NULL Message" command packet as follows;

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

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

Command code

STX 'B' 'E' ETX

Contents

Main EXTERNAL CONTROL NEC LCD Monitor Rev.3.5 INDEX Page I. Application II. Preparation 2. Connectors and wiring 2.1 RS-232C Remote control 2.2 LAN control III. Communication specification 3. Communication Parameter 3.1 RS-232C Remote control 3.2 LAN control 3.3 Communication timing 4. Communication Format Get Parameter Monitor Controller 4.1 Header block format (fixed length) Page 4.2 Message block format Page 4.3 Check code 4.4 Delimiter 5. Message type 5.1 Get current Parameter from a monitor. and 32h). 5.2 "Get parameter" reply 5.3 Set parameter : ( 5.4 "Set parameter" reply 5.5 Commands . 5.5.1 Save Current Settings. 5.5.2 Get Timing Report and Timing reply. 5.5.3 NULL Message IV. Control Commands 6. Typical procedure example 6.1. How to change the Backlight setting. Page Page 6.2. How to read the measurement value of the built-in temperature sensors. Page Page 6.3. Operation Code (OP code) Table PICTURE ADJUST AUDIO SCHDULE PIP OSD MULTI DISPLAY DISPLAY PROTECTION Advanced Option Page Page Temperature sensor Carbon footprint 7. Power control procedure 7.1 Power status read Page 7.2 Power control 1) The controller requests the monitor to control monitor power. Page 8. Asset Data read and write 8.1 Asset Data Read Request and reply Page 8.2 Asset Data write Page 9. Date & Time read and write 9.1 Date & Time Read Page 9.2 Date & Time Write Page Page 10. Schedule read and write 10.1 Schedule Read This command is used in order to read the setting of the Schedule. Page Page Page Page 10.2 Schedule Write This command is used in order to write the setting of the Schedule. 1) The controller requests the monitor to write Schedule. Page Page The controller requests the monitor to write Enable/Disable Schedule. Page Page 1) The controller requests the monitor to write Schedule. Page The controller requests the monitor to write Enable/Disable Schedule. Page 11. Self diagnosis 11.1 Self-diagnosis status read This command is used in order to read the Self-diagnosis status. Page 12. Serial No. & Model Name Read 12.1 Serial No. Read This command is used in order to read a serial number. 12.2 Model Name Read This command is used in order to read the Model Name. 13. Security Lock 13.1 Security Lock Control This command sets the condition of security lock function to "LOCK" or "UNLOCK". Page 14. Direct TV Chanel Read & Write When DTV unit (Option unit) is installed, channel setting is read and write directly. 14.1 Direct TV Chanel Read & Reply 14.2 Direct TV Chanel Write & Reply