LDM231-251 RS-232 Protocol

RS-232

This document describes the hardware interface and software protocols of RS-232 interface communication between the ViewSonic LED Display and computers or other control units with RS-232 protocol.

RS-232 Hardware Specification

ViewSonic RS-232 serial port on the lower left side:

1. Connector type: DB 9-Pin Female
2. Use of straight-through parallel cable for connection
3. Pin Assignment:

	Pin #	Signal	Remark
Female DB 9-Pin	1	NC
	2	TXD	Output from Display
	3	RXD	Input to Display
	4	NC
	5	GND	GND
	6	NC
	7	NC
	8	NC
	9	NC
	frame	GND

RS-232 Communication Setting

Baud Rate Select:	9600bps (fixed)
Data Bits:	8 bits (fixed)
Parity:	None (fixed)
Stop Bits:	1 (fixed)

Note: Make sure the Control Board Switch is switched to the left for RS-232 control.

Command Table

Function	Command Code (Hex)	HEX	Data Range
Power on/off(standby):STBY	21	38 30 31 73 21 30 30 30 0D
Power on/off(standby):ON	21	38 30 31 73 21 30 30 31 0D
Input Select:USB auto play	22	38 30 31 73 22 30 30 33 0D
Input Select:HDMI1	22	38 30 31 73 22 30 30 34 0D
Input Select:HDMI2	22	38 30 31 73 22 30 31 34 0D
Input Select:HDMI3	22	38 30 31 73 22 30 32 34 0D
Input Select:HDMI4	22	38 30 31 73 22 30 33 34 0D
Brightness	24	38 30 31 73 24 3X 3X 3X 0D	000-100
Brightness:Bright down (-1)	24	38 30 31 73 24 39 30 30 0D
Brightness:Bright up (+1)	24	38 30 31 73 24 39 30 31 0D
Power lock:Unlock	34	38 30 31 73 34 30 30 30 0D
Power lock:Lock	34	38 30 31 73 34 30 30 31 0D
Volume	35	38 30 31 73 35 3X 3X 3X 0D	000-100
Volume:Volume down(-1)	35	38 30 31 73 35 39 30 30 0D
Volume:Volume up(+1)	35	38 30 31 73 35 39 30 31 0D
Mute:OFF	36	38 30 31 73 36 30 30 30 0D
Mute:ON	36	38 30 31 73 36 30 30 31 0D
Button lock:Unlock	38	38 30 31 73 38 30 30 30 0D
Button lock:Lock	38	38 30 31 73 38 30 30 31 0D
Menu lock:Unlock	3E	38 30 31 73 3E 30 30 30 0D
Menu lock:Lock	3E	38 30 31 73 3E 30 30 31 0D
Key Pad:UP	41	38 30 31 73 41 30 30 30 0D
Key Pad:DOWN	41	38 30 31 73 41 30 30 31 0D
Key Pad:LEFT	41	38 30 31 73 41 30 30 32 0D
Key Pad:RIGHT	41	38 30 31 73 41 30 30 33 0D
Key Pad:ENTER	41	38 30 31 73 41 30 30 34 0D
Key Pad:INPUT	41	38 30 31 73 41 30 30 35 0D
Key Pad:MENU/(EXIT)	41	38 30 31 73 41 30 30 36 0D
Key Pad:EXIT	41	38 30 31 73 41 30 30 37 0D
Key Pad:power on/off	41	38 30 31 73 41 30 30 38 0D
Key Pad:inputlist	41	38 30 31 73 41 30 30 39 0D
Key Pad:brightness	41	38 30 31 73 41 30 31 30 0D
Key Pad:blank	41	38 30 31 73 41 30 31 31 0D
Key Pad:home	41	38 30 31 73 41 30 31 32 0D
Key Pad:volume+	41	38 30 31 73 41 30 31 33 0D
Key Pad:volume-	41	38 30 31 73 41 30 31 34 0D
Key Pad:next	41	38 30 31 73 41 30 31 35 0D
Key Pad:previous	41	38 30 31 73 41 30 31 36 0D
Key Pad:mute	41	38 30 31 73 41 30 31 37 0D
Key Pad:play	41	38 30 31 73 41 30 31 38 0D

Get Operation Time Example

Assumed the accumulated operation time is 00,123,456 hrs.

• Send: 38 30 31 67 31 30 30 30 0D (Get Operation time)
• Reply: 32 30 31 72 31 31 32 33 34 35 36 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0D