USB to Serial Adapter

The Beagle Software USB to Serial Adapter allows you to use Beagle Software's serial hardware with your USB equipped laptop or desktop computer . The  USB to Serial adapter connects RS-232 serial devices to your USB-equipped Windows host computer. It provides a bridge connection with a standard DB 9-pin male serial port connector in one end and a standard Type-A USB plug connector on the other end. You simply attach your Beagle Software device to the DB 9-pin end of the adapter cable and plug the USB connector into your PC's USB port.

Features & Specifications
  • Smart USB to RS-232 (DB 9-pin male serial port) interface. 2 foot integrated cable.
  • Supports  serial devices including DocuClock printers, Star Sync and Radio Sync receivers. Can also be used with  modems, PDAs, cellular phones, digital cameras, card readers, and more.
  • Easy Plug and Play Installation. No IRQ resource required
  • Full compliance with the Universal Serial Bus Specification v1.1. Compatible with USB v2.0 ports
  • Supports the standard RS-232 Serial Interface. Supports automatic handshake mode
  • 1 mega baud maximum data transfer rate. Provides dual buffers for upstream and downstream data transfer
  • Supports Remote Wake-up and Intelligent Power Management.  Supports advanced power management such as suspend and resume operations as well as remote wakeup.
  • USB Powered – no separate power supply or battery required
Price  Catalog number: 232USB
System Requirements
  • Windows 98, Windows ME, Windows 2000, Windows XP  or Windows 2003 operating system
  • AMD or Intel Pentium 133MHz or better based computer
  • USB 1.1 or higher port
  Installation and Configuration

How to Install the Driver

1) Plug the Cable into a USB port.
2) The “Welcome to the Found New Hardware Wizard”  or "Add New Hardware Wizard" (Win98) should appear. If it doesn’t appear, go to step 9.
3) Ensure the product driver CD (included with package) has been inserted in your CD-ROM drive.
4) Select the option: “Install the software automatically (Recommended).” or "Search for the best driver for your device" (Win98)
5) Press “Next”. Win 98 users should check CD-ROM drive.
6) Windows should find the “Prolific USB-to-Serial Comm Port” driver. Otherwise you should find the directory under your version of Windows under the "USB to RS232 1.1" directory on the CD-ROM. Windows 98 lists the device as "GM USB to Serial Bridge"
7) You will probably see a message indicating that the driver has not passed Windows Logo testing. Press “Continue Anyway.” This warning can be safely ignored.
8) Press “Finish” when prompted by Windows to complete the installation.

*** If the “Found New Hardware Wizard” did not appear in step 2 ***
9) Open Device Manager by doing the following:
   a) Click on “Start” and then “Control Panel.”
   b) Switch to Classic View (if in Category View).
   c) Double click on “System.”
   d) Select the Hardware tab.
   e) Press the “Device Manager” button.
10) Under “Ports (COM & LPT),” look for a USB Device entry with a yellow exclamation point '!' by it.
11) Right click on the USB Device and select “Update Driver.”
12) This should bring up the “Welcome to the Hardware Update Wizard.”
13) Ensure the product driver CD (included with package) is inserted in your CD-ROM drive.
14) Select the option: “Install the software automatically (Recommended).”
15) Press “Next.” Continue from step 5 above.

How to Check the Driver Installation

1) Go to the Device Manager:

Windows XP:  Start -> Control Panel -> System -> Hardware -> Device Manager

Windows 2000/2003:  Start -> Settings -> Control Panel -> System -> Hardware -> Device Manager

Windows 98/ME: Start -> Settings -> Control Panel -> System -> Device Manager

2) Click on the plus sign (+) next to "Ports."

3) If the device is installed properly, you will see "Prolific USB-to-Serial Comm Port. (COMx)" or "USB to Serial Port (COMx)" (Win98). Note that x is the number of the COM port (typically 1-8)  assigned to the adapter.

The driver is installed properly, but the device is not working

First check to see that the Beagle Software application is set to the correct COM port number. To determine the COM port number assigned to the adapter, check the Device Manager (see above).

It is also possible that the COM port number assigned is too high. Sometimes a device won't  work with the USB-to-Serial adapter even though everything appears to have installed correctly because some computers will only scan a limited number of COM ports.

For instance, it is possible that a computers has a limitation of scanning the first four COM ports. If the adapter is installed on COM5, a device with such a limitation will not work until the COM port is reassigned to COM1 - COM4.

Windows XP, 2000, ME, and 98  include a function that allows you to reassign the COM port.  Simply follow the instructions below:

Windows XP port reassignment

1) Follow steps 1 and 2 in "How to Check the Driver Installation."

2) Right click on the "Prolific USB to Serial Port" and click on Properties

3) Click on the "Port Settings" tab. Click the "Advanced" button.

4) Pull down the scrollbar on the bottom, left side and select COM 1, 2, 3 or 4 (NOTE: Choose one that does not say "in use" next to it). Click "OK."

5) Click "OK" again. Notice that the device will show up as being on the same COM port that it was before (i.e., COM5), but will show up on the new port if you close the Device Manager and open it again.

6) Close the device manager. You may have to run the software that came with your device to make it rescan the COM ports.

Windows 2000, ME, and 98SE port reassignment

1) Follow steps 1 and 2 in "How to Check the Driver Installation."

2) Right click on the "Prolific USB to Serial Port" and click on Properties

3) Click on the "Port Settings" tab. Click on the Resources tab.

4) Uncheck the box that says "Use automatic settings".

5) Select "Input/Output range".  Click on "Change Settings".

6) Type "02E8-02EF" in the Value box.  This value will change the port to COM 4.  If COM 4 is in use, you must choose another port.  The values for each port are:

COM 1:  03F8-03FF

COM 2:  02F8-02FF

COM 3:  03E8-03EF

COM 4:  02E8-02EF

7) After entering the value, click OK.  Click OK again and click Yes when the "Creating a Forced Configuration" window appears.  Click OK again.

8) Restart your computer.  If you go into the device manager, you will see that the COM port has changed to the one you have selected.

Technical Support:

If you are having problems with the USB-to-Serial Adapter that this page does not address, please feel free to contact us at .


For More Information

DocuClock Time Stamper

Star Sync GPS time receiver

Radio Sync WWVB time receiver



Copyright 2004 Beagle Software. All rights reserved
Last reviewed September 13, 2004