DS_USB-COM422-PLUS1 Datasheet, PDF (3/23 Pages) List of Unclassifed Manufacturers – Future Technology Devices International Ltd

1.2 LED Description
Document Reference No.: FT_000131
USB-COM422-PLUS1 Datasheet
Version 1.1
Clearance No.: FTDI# 94
The USB-COM422-Plus1 uses three LEDs to indicate a valid link as well as data traffic according to the
following table:
LED Color Function Description
Yellow
Enumerated ON when USB-COM422-Plus1 is configured and ready
Green
TxD Activity
Flashes when data is transmitted from the USB-COM422-Plus1 to the
attached RS422 device
Red
RxD Activity
Table 1.1 LED Description
Flashes when data is transmitted from the attached RS422 device to the
USB-COM422-Plus1
1.3 Block Diagram
USB B
Client
Connector
FTDI FT232R
USB Serial Bridge
RS422
Level Shifter
DE-9P
Connector
Figure 1.2 USB-COM422-Plus1 Block Diagram
1.3.1 Block description
USB B Client Connector
This connector provides the interface for connection to a USB Host or Hub port. The maximum cable
length is 5 meters, according to the USB 2.0 specification.
FTDI FT232R
The FTDI FT232R provides the USB-to-Serial conversion. Operating system device drivers are required in
order to work with the FT232R to provide the Virtual COM Port serial functionality.
RS422 Level Shifter
The RS422 level shifter converts the signals provided by the FT232R into the voltage levels required by
RS422 devices.
DE-9P Connector (Male)
The DE-9P connector is configured in an industry standard (TIA/EIA-574) pin-out to provide connection to
RS422 peripherals through standard cables. See section 3.1.2
Copyright © 2010 Future Technology Devices International Limited
2