The device connected to a UPort COM port or a multi-port card is identified as PnP serial mouse and a cursor jumps around the screen

This problem can be misinterpreted as a problem with a multi-port card or a driver from MOXA, however, it is caused by Microsoft Windows 2000 / XP / 2003 / 7 OS.

This problem can be misinterpreted as a problem with a multi-port card or a driver from MOXA, however, it is caused by Microsoft Windows 2000 / XP / 2003 / 7 OS.

The problem lies within Plug&Play function in Windows. When Windows is booting, the OS tries to identify new devices my requesting each communication interface, including COM ports. If there is data transmission ongoing via a COM port, Windows OS will mistake it for a response to its request and compare it to the system register and the device manager.

It will identify the serial device as a new device. As a rule, Windows will take it for a serial mouse and it will interfere with the original mouse. Such behaviour is typical for any version of Microsoft Windows.

Solution:

  1. Switch off the serial device until Windows OS is completely booted.
  2. Refer to Microsoft Knowledge Base: https://support.microsoft.com/en-us/kb/283063
  3. Microsoft also provides the COMDisable utility tool. To find out more, visit Microsoft Knowledge Base: https://support.microsoft.com/en-us/kb/819036
We use cookies to enhance your browsing experience, serve personalized ads or content, and analyze our traffic. By clicking "Accept All", you consent to our use of cookies. Cookie Policy.