IFP50-3 RS-232 Protocols

RS-232 Protocol

This document describes the hardware interface spec and software protocols of RS-232 interface communication between ViewSonic LFD and PC or other control units with RS-232 protocol.

The protocol contains three command sections:

• Set-Function
• Get-Function
• Remote control pass-through mode

NOTE: Below, “PC” represents all the control units that can send or receive the RS-232 protocol command.

Description

RS-232 Hardware Specification

ViewSonic LFD communication port on the rear side:

1. Connector type: DSUB 9-Pin Male (or 3.5 mm barrel connector)
2. Use of crossover (null modem) cable for connection
3. Pin Assignment:

	Pin #	Signal	Remark
Female DSUB 9-Pin	1	NC
	2	RXD	Input to Display
	3	TXD	Output to Display
	4	NC
	5	GND
Male DSUB 9-Pin	6	NC
	7	NC
	8	NC
	9	NC	Provide +5V/2A power for external specific dongle *3.0
	frame	GND

	Item	Signal	Remark
3.5 mm barrel connector (alternative for limited space)	Tip	TXD	Output to Display
	Ring	RXD	Input to Display
	Sleeve	GND

LAN Hardware Specification

ViewSonic LFD communication port on the rear side:

1. Connector type: 8P8C RJ45
2. Pin assignment:

	Pin #	Signal	Remark
	1	TX+	Output from Display
	2	TX-	Output from Display
	3	RX+	Input to Display
	4	BI_D3+	For 1G case
	5	BI_D3-	For 1G case
	6	RX-	Input to Display
	7	BI_D4+	For 1G case
	8	BI_D4-	For 1G case
	frame	GND

RS-232 Communication Setting

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

LAN Communication Setting

• Type: Ethernet
• Protocol: TCP/IP
• Port: 5000 (fixed)
• Cross subnet: No
• Logon Credentials: No

Command Message Reference
PC sends to LFD command packet followed by “CR”. Every time PC sends control command to Display, the Display shall respond as follows:

1. If the message is received correctly it will send “+” (02Bh) followed by “CR” (00Dh)
2. If the message is received incorrectly it will send “-” (02Dh) followed by “CR” (00Dh)

Protocol

Set-Function Listing

The PC can control the Display for specific actions. The Set-Function command allows you to control the Display behavior at a remote site through the RS-232 port. The Set-Function packet format consists of 9 bytes.

Set-Function Description:

Length	Total Byte of Message excluding “CR”
LFD ID	Identification for each of Display (01~98; default is 01) ID “99” means to apply the set command for all connected displays. Under such circumstances, only ID#1 display has to reply. The LFD ID can be set via the OSD menu for each Display.
Command Type	Identify command type, "s" (0x73h): Set Command "+" (0x2Bh): Valid Command Reply "-" (0x2Dh): Invalid Command Reply
Command	Function command code: One byte ASCII code.
Value [1~3]	Three bytes ASCII that defines the value.
CR	0x0D

Set-Function Format Send: (Command Type="s")

Name	Length	ID	Command Type	Command	Value1	Value2	Value3	CR
Byte Count	1 Byte	2 Byte	1 Byte	1 Byte	1 Byte	1 Byte	1 Byte	1 Byte
Bytes Order	1	2~3	4	5	6	7	8	9

Reply: (Command Type="+" or "-")

Name	Length	ID	Command Type	CR
Byte Count	1 Byte	2 Byte	1 Byte	1 Byte
Bytes Order	1	2~3	4	5

NOTE: When PC applies command to all displays (ID=99), only the #1 set needs to reply by the name of ID=1.

Example 1: Set Brightness as 76 for Display (#02) and this; command is valid.

Send (Hex Format)

Name	Length	ID	Command Type	Command	Value1	Value2	Value3	CR
Hex	0x38	0x30 0x32	0x73	0x24	0x30	0x37	0x36	0x0D

Reply (Hex Format)

Name	Length	ID	Command Type	CR
Hex	0x34	0x30 0x32	0x2B	0x0D

Example 2: Set Brightness as 75 for Display (#02) and this; command is NOT valid.

Send (Hex Format)

Name	Length	ID	Command Type	Command	Value1	Value2	Value3	CR
Hex	0x38	0x30 0x32	0x73	0x24	0x30	0x37	0x35	0x0D

Reply (Hex Format)

Name	Length	ID	Command Type	CR
Hex	0x34	0x30 0x32	0x2D	0x0D

Set-Function Table

A. Basic Function