Configuring a PC USB port as a virtual serial port

It is possible to use the USB interface from a Trimble R980 receiver with a software application that requires a serial port.

For example, the Trimble Installation Manager can be run on a computer that has no physical serial port by connecting the USB cable between the computer and the receiver.

This step is not necessary for Windows 10, or if you have previously installed the Trimble USB driver.

Windows 10 operating system

Unlike Windows 8 and previous versions of the Windows operating system you do not need to load the USB installer. Windows 10 will automatically create the USB virtual serial port once it detects a Trimble GNSS device is plugged in. The Windows Device Manager will show you the virtual COM port that is created when the receiver is connected by USB.

Windows 8 operating system

  1. The simplest way to install the virtual serial port for the USB interface to the receiver is to go to the Trimble Support website (www.trimble.com/en/support/overview) and search for the GNSS receiver you have. In the Technical Support / Downloads section, download the file called Windows7 USB Installer to your computer.

    There is no Windows8 USB Installer file; the Windows7 USB Installer file works for Windows 8.

    This file contains a Support Note and installation program.

  2. Run the installation program. It will load the virtual serial port for the USB interface on your computer .

    With Windows 8, the USB ports are often version 3.0. With Windows 8 there is a conflict with the implementation of USB version 3.0. To workaround this, go to the computer's BIOS settings when you start up the computer and then turn off the support for USB 3.0.

If you are running an application such as WinFlash software or Trimble Installation Manager on the computer and you physically disconnect the USB cable from the computer and then reconnect it, it does not always re-establish the connection. This is because opening the serial port from the application locks the device handle and when the USB device is disconnected, the application does not close the serial port and the device handle is still locked. On reconnecting, the USB cable is unable to get the device handle since it is locked. You must close the application before the reconnect to the port will work. This limitation is due to the behavior of the Microsoft USB serial driver.