Copyright © 2010 Future Technology Devices International Limited

11

Document Reference No.: FT_000131

USB-COM422-PLUS1 Datasheet

Version 1.1

Clearance No.: FTDI# 94

3 Connections

3.1.1 USB

The USB-COM422-Plus1 is a downstream USB 2.0 Device. A standard USB Series “B” receptacle is

reference to USB-F-1001 to facilitate connection to an upstream USB Host or Hub.

Pin Number

Pin Type

Description

1

Power

VBUS = USB Power provided from upstream USB Host or Hub

2

Bidirectional

D– = USB data signal, negative polarity

3

Bidirectional

D+ = USB data signal, positive polarity

4

Ground

GND = USB signal ground

Shield

Case Ground

Drain = typically connected to the host PC case

Table 3.1 USB "B" Receptacle Pin-Out

3.1.2 RS422

The RS422 port is configured as Data Terminal Equipment (DTE), with a 9-contact D-Sub Pin connector.

Pin assignments are according to TIA/EIA-422.

Pin Number

Pin Type

Description

1

Output

TXD- = Transmit Data, negative polarity

2

Output

TXD+ = Transmit Data, positive polarity

3

Input

RXD+ = Receive Data, positive polarity

4

Input

RXD- = Receive Data, negative polarity

5

Ground

GND = signal ground

6

Output

RTS- = Request To Send, negative polarity

7

Output

RTS+ = Request To Send, positive polarity

8

Input

CTS+ = Clear To Send, positive polarity

9

Input

CTS- = Clear To Send, negative polarity

Table 3.2 DE-9P RS422 Pin-Out