Tripp Lite
1111 W. 35th Street
Chicago, IL 60609
+1 (773) 869-1776
+1 (773) 869-1329

4-Port RS-422/RS-485 USB to Serial FTDI Adapter with COM Retention (USB-B to DB9 F/M)

USB to serial converter lets you connect four 9-pin serial devices to your computer or laptop’s USB-A port.
  • Auto-detects and -switches RS-422 and RS-485 serial devices
  • Independent DIP switch controls provide easy port configuration
  • Automatically reassigns COM values to each port to avoid additional configuration
  • USB-powered, so no bulky or obtrusive external power supply is required
  • Compatible with Windows, Mac and Linux—works with most computers
  • 2-year limited warranty

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Connects Up to Four 9-Pin Serial Devices to Your Computer, Laptop or Tablet’s USB-A Port
This USB to serial converter turns your computer’s USB port into four DB9 ports capable of connecting RS-422 and RS-485 serial devices, such as modems, handheld scanners and GPS systems. No external power source is needed. Just connect the included USB cable between the U208-004-IND and your computer, and insert the included CD into your computer’s CD drive in order to launch the driver. You’ll be able to configure and share data among point-of-sale equipment and other serial devices. LEDs indicate when serial data is being sent or received.
Independent DIP Switches for Easy Port Configuration
The U208-004-IND’s serial ports can be set to automatically detect an RS-422 or RS-485 device by adjusting their DIP switch settings. The ports can also be set specifically for use in 4-wire mode.
COM Retention Feature for Convenient Reassigning of COM Values to Ports
This USB to RS-485 adapter with built-in FTDI chipset offers COM retention. It automatically reassigns the same COM port values to each port, so when the cable is disconnected or the system is rebooted, no additional configuration is needed. The cable auto-detects and auto-switches RS-422 and RS-485 devices. It also supports RS-485 auto-transceiver turn around with unique featured ATTA hardware.
Rugged All-Metal Housing Designed to Last in Harsh Industrial Applications
The wall-mountable USB to serial converter with an industrial-grade steel enclosure offers electrostatic discharge (ESD) protection to ±15kV. It supports serial communications speeds up to one Mbps and USB 2.0 specifications, though it is backward compatible with USB 1.1 devices.
2-Year Warranty
The U208-004-IND is backed by a 2-year warranty, ensuring reliability and performance.

Typical Applications

  • Connect and control 9-pin point-of-sale devices, including barcode scanners and credit card readers
  • Activate surveillance cameras, access panels and other security equipment
  • Operate serial-based medical and scientific instruments, such as bedside monitors and nursing call stations

Package Includes

  • U208-004-IND RS422/485 USB to Serial FTDI Adapter
  • USB-A to USB-B cable (M/M), 3 ft.
  • (8) 2-pin jumpers
  • Driver CD
  • Owner’s manual

System Requirements

  • Windows XP or later
  • Mac OS X 10.4 or later
  • Linux 2.6.31 or later
  • Computer with an available USB port
RoHS compliant


UPC Code037332205988
Voltage Compatibility (VAC)100; 110; 120; 127; 200; 208; 220; 230; 240
Bus Powered  Yes
External Power Supply Input Specs (V / Hz / A)100-240V / 50/60Hz / 0.6A
External Power Supply Output Specs (V / A)5V / 1A
DC Barrel PlugOD: 5.5 x 2.1 x 9.5mm, Positive Pin, Negative Sleeve
LED IndicatorsGreen (Serial Data Received), Yellow (Serial Data Sent)
Material of ConstructionSteel (Galvanized Cold Rolled)
Shipping Dimensions (hwd / in.)2.20 x 5.90 x 8.90
Shipping Weight (lbs.)1.10
Unit Dimensions (hwd / in.)0.9 x 6.8 x 2.4
Unit Packaging TypeBox
Unit Weight (lbs.)0.62
Operating Temperature Range32 to 104 F (0 to 40 C)
Storage Temperature Range14 to 131 F ( -10 to 55 C)
Relative Humidity5% to 90% RH, Non-Condensing
BTUs  15.4 BTU/Hr
Power Consumption (Watts)4.5
Side A - Connector 1USB B (FEMALE)
Side B - Connector 1(4) DB9 (MALE)
Connector PlatingNickel
Contact Plating  Gold
USB SpecificationUSB 2.0 (up to 480 Mbps)
Driver RequiredYes
CertificationsTested to CE, FCC, RoHS, REACH
Product Warranty Period (Worldwide)2-year limited warranty

Questions & Answers

COM retention allows the same COM port number to be automatically assigned each time the serial adapter is connected to a USB port on your system (or your system is rebooted). Without COM Retention, you would have to remember which port to connect the adapter.
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+1 (773) 869-1776

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+1 (773) 869-1234

Tripp Lite
1111 West 35th Street
Chicago, Illinois 60609
United States

+1 (773) 869-1111 Main
1 773.869.1329 Fax

Business Hours
8 AM - 5:30 PM CST

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