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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:
Female DSUB 9-Pin
Male DSUB 9-Pin
Pin # Signal
Remark
1
NC
2
RXD
Input to Display
3
TXD
Output from Display
4
NC
5
GND
6
NC
7
NC
8
NC
9
NC
P5V/2A power for external
specific dongle *3.0
frame GND
3.5 mm barrel
connector (alternative
for limited space)
Item Signal
Remark
Tip
TXD
Output from Display
Ring
RXD
Input to Display
Sleeve
GND