USB-COM485-PLUS-2 FTDI, Future Technology Devices International Ltd, USB-COM485-PLUS-2 Datasheet - Page 14

• Manufacturer Part Number: USB-COM485-PLUS-2
• Description: MODULE USB TO RS485 CONV DUAL HS
• Manufacturer: FTDI, Future Technology Devices International Ltd
• Series: USB-COM-Plusr

Specifications of USB-COM485-PLUS-2

• Convert From (adapter End): USB-B
• Convert To (adapter End): DE-9P Male (2)
• Features: USB Hi-Speed to RS485 Serial Converter Assy, w/LEDs, 10Mbps
• For Use With/related Products: Windows® 2000 or higher, Linux, Max OS X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 768-1039; USB-COM485-PLUS-2

3.1.2 RS485
The RS485 ports are configured as Data Terminal Equipment (DTE), with a 9-contact D-Sub Pin
connector. Pin assignments are according to TIA/EIA-485. In addition, pin9 of DB9 provides +5VDC to
an external device with a maximum current draw of 450mA once the USB-COM485-PLUS2 has been
enumerated by the system. Both D-type connectors have a similar connection as described in Table 3.2.
Table 3.2 – DE-9P RS485 Pin-Out
Pin Number
1
2
3
4
5
6
7
8
9
PWR = +5V DC output
GND = signal ground
Copyright © 2010 Future Technology Devices International Limited
Input/Output
Input/Output
Pin Type
Output
Input
Input
N/A
N/A
Description
COM485-PLUS2 is the first or last device in a multi-drop RS485
COM485-PLUS2 is the first or last device in a multi-drop RS485
Pin 2 of 120R Terminating Resistor. Only Required if the USB-
Pin 1 of 120R Terminating Resistor. Only Required if the USB-
Pin 7 of the local echo control. Connect to pin 8 of the echo
Connect to pin 7 of the echo control to disable local echo.
control to disable local echo. Default is that local echo is
System, to meet RS485 Termination Requirements.
System, to meet RS485 Termination Requirements.
Default is that local echo is enabled.
enabled.
DATA+
DATA-
GND
PWR
Document Reference No.: FT_000136
N/A
N/A
USB-COM485-PLUS2 Datasheet
Clearance No.: FTDI#104
Version 1.2
13