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	21	38 30 31 73 21 30 30 31 0D
Power Off (Standby)	21	38 30 31 73 21 30 30 30 0D
Get-Power Status	6C	38 30 31 67 6C 30 30 30 0D
Input Select: HDMI 1	22	38 30 31 73 22 30 30 34 0D
Input Select: HDMI 2	22	38 30 31 73 22 30 31 34 0D
Get-Input Select	6A	38 30 31 67 6A 30 30 30 0D
Input Select: Home	22	38 30 31 73 22 30 30 41 0D
Brightness: Down (-1)	24	38 30 31 73 24 39 30 30 0D
Brightness: Up (+1)	24	38 30 31 73 24 39 30 31 0D
Volume: Down (-1)	35	38 30 31 73 35 39 30 30 0D
Volume: Up (+1)	35	38 30 31 73 35 39 30 31 0D
Get-Volume	66	38 30 31 67 66 30 30 30 0D
Mute: OFF	36	38 30 31 73 36 30 30 30 0D
Mute: ON (mute)	36	38 30 31 73 36 30 30 31 0D
Get-Mute	67	38 30 31 67 67 30 30 30 0D
Number (0~9)	40	38 30 31 73 40 30 30 3x 0D	x = 0~9
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	41	38 30 31 73 41 30 30 36 0D
Key Pad: EXIT	41	38 30 31 73 41 30 30 37 0D
Get-Operational Hours	31	38 30 31 67 31 30 30 30 0D