1. Replacing Digitus 1.1 Serial Converter with Digitus 2.0


In May 2019 the WIN-911 QA team recently discovered an issue with the Digitus Serial Converter 1.1 and it is not as reliable as the 2.0 version. The modem commands are not received by WIN-911, which will result in an echo timeout message from the device. The recommendation is to use 2.0 version and this article will discuss the process for removing the 1.0 device and installing the 2.0 drivers. 

A. Procedure 

The Digitus Serial Converter comes with a USB extension cord and a CD containing device drivers. If the drivers on the disk do not match the drivers found in this document use the document.

B. Serial Converter 1.1 Removal

1. Open Device Manager, find the USB Serial Converter under other devices.

2. Expand the Ports selection and right click your Prolific USB-to-Serial Comm Port device/port.


3. Right-click the Prolific device/port and select uninstall. When prompted select the Delete the driver software for this device option and select Uninstall.

            4. Disconnect the Digitus USB Serial Converter 1.1 from your computer, then disconnect the Digitus USB                 Serial Converter 1.1 from your Modem.

            5. Verify that the Prolific USB-to-Serial Comm Port is no longer a device/port under your Ports.

C. Digitus USB Serial Converter 2.0 Installation


1. Connect the DB9 male connector (9-pin) of the RS-232 cable to the RS-232 connector on the modem, then connect the other end to the serial port on the Digitus USB Serial Converter.

2. Screw-on the power lead from the power supply adapter into the power connection on the modem.

3. Plug the Digitus USB Serial Converter into the computer. Windows will detect the new device and be unable to install a driver. (Users who see their converter recognized as

4. Download and extract the driver from this ZIP file.

5. Open Device Manager, find the USB Serial Converter under Other Devices.

6. Right-click USB Serial Converter and select Update Driver Software

7. Select Browse my computer for driver software

8. Select Browse... and navigate to the driver folder you extracted

9. Windows will install the driver for the USB Serial Converter. 

10. You will now have an unknown device called USB Serial Port under Other devices.

11. Right-click USB Serial Port and select Update Driver Software.  

12. Select Browse my computer for driver software.

13. Select Browse... and navigate to the same driver folder you used earlier

14. Windows will install the driver and you'll now see USB Serial Port under Ports (COM & LPT).

15. The Digitus USB Serial Converter is now installed and your modem can be accessed via the port it has been assigned. In this example, the modem is located on COM3.

The Digitus 1.1 Serial Converter has now been replaced with the Digitus 2.0 Serial Converter for use with your SMS modem.

Technical Support

To create a support case, you will need either your Maintenance Support number or your CD Tracking number. You can create a Case online or contact the product support line: (512)326-1011.