8.1. No device found / Can’t open device

8.1.1. Connect via USB

XiLab or other software can not find the controller.

  • The PC does not detect the controller via USB:

Comment to the scheme:

The most common cause for such type of problem is bad work of the usb-hub, cables or the virtual COM-port identification problem of the operation system on the used PC. Try to reproduce the problem on the another PC or another usb-hub if it is used.


“Can’t open device” error or “open_device()” function returns -1. Libximc library opens the controller in exclusive access mode. Any controller opened with libximc (XiLab also uses this library) needs to be closed before it may be used by another process. So at first check that you have closed XiLab or other software dealing with the controller before trying to reopen the controller.

Below are the action maps for the not found controller.



Comments to the scheme:

  • Check whether the COM-port corresponding to your controller presents in the Device manager. It should be displayed as “XIMC Motor Controller (COMn)”. In case the controller has not been recognized, try to reinstall the driver for the controller manually.
  • Try to open the COM-port of the controller in any simple serial emulator (Putty for example) and just send the simple command to the controller (like “stop”, “sstp”, “zero”, “GETS”, “GETI”). The connection parameters are described here. The absence of errors means that the controller is operating correctly and the problem should be caused by the used software.

Video guide for reinstalling the driver



Comment to “Can’t open device” problem solution:

When working with USB-UART converter (as well as USB-Ethernet, USB-Bluetooth etc.) in Linux it appears as /dev/ttyUSB device. XiLab shows it in a list, but when you try to open it, an error “can’t open device” occurs due to the lack of permissions to the device.

To solve this problem, create a file: /etc/udev/rules.d/31-ximc.rules and add the next line into it:

SUBSYSTEM=="usb", ATTR{idVendor}=="067b", MODE="0666"

idVendor identifier can be found by executing lsusb command.


One possible solution to the “device not found” problem is to add a user to the dialuot group. Important: after adding it, you must restart your computer.

Mac OS:


8.1.2. Connect via ETHERNET

  • Is a DHCP server installed on your network?
    If yes:
    • Make sure that the controller is assigned an IP address
    • Make sure that the controller is on the same subnet as your computer
    If not:
    You can install a DHCP server or use a static IP address.
  • Is your controller visible in the “Revealer” program?
    If yes:
    • To access the administration panel, click on the IP address. If the control panel opens (use “admin” as login and password), your controller works fine!
    If not:
    • Reboot your controller or 8Eth1 [1] adapter
    • Connect the controller to your computer via USB and make sure it works correctly
      We recommend using xilab for verification
    • Disable “Windows Defender Firewall” and click the “Search”
    • Try to reproduce the problem on another computer


Send your questions with a detailed description of the problem to tech support:

[1]The vendor code was changed in 2020, earlier this product had the vendor code 8SMC4-USB-Eth.