Recommended BIOS Settings for Quad-Serial USB Controllers

Recommended BIOS Settings for Quad-Serial USB Controllers

The quad-serial USB controller allows connecting more RS232 RJ45 serial devices via the USB ports.  However, there is a limitation on how many USB endpoints are supported by the default BIOS settings.  If the ports on a quad-serial USB controller are not being detected automatically, the BIOS settings may need to be adjusted to allow more endpoints.

  1. Arrange Console access to the unit using terminal settings:

    1. 115200bps

    2. 8 bits

    3. No parity

    4. 1 stop bit

    5. No flow control

  2. Reboot the system

    1. Login as admin

    2. Issue command: reboot

    3. Confirm reboot: yes

  3. After beep/screen clear, press Shift-D to access the Advanced BIOS

  4. Navigate to the Configuration tab

  5. Select the USB Configuration sub-menu:

  6. Verify settings show:

    1. Legacy USB Support: Enabled

    2. XHCI Legacy Support: Disabled

    3. XHCI Hand-off: Disabled

    4. EHCI Hand-off: Enabled

    5. USB Mass Storage Driv: Enabled

  7. Select the USB Configuration sub-menu:

  8. Verify settings show:

    1. USB OTG Support: Disabled

    2. USB VBUS: Disabled

    3. USB 2.0(EHCI) Support: Enabled

    4. USB EHCI debug: Disabled

    5. USB Port 0: Enabled

    6. USB Port 1: Enabled

    7. USB Port 2: Enabled

    8. USB Port 3: Enabled

  9. Navigate to the Advanced tab

  10. Select the USB Configuration sub-menu:

  11. Verify settings show:

    1. XHCI Legacy Support: Disabled

    2. XHCI Hand-off: Disabled

    3. EHCI Hand-off: Enabled

    4. USB Mass Storage Driv: Enabled

    5. USB transfer time-out: 20 sec

    6. Device reset time-out: 20 sec

    7. Device power-up delay: Auto

  12. If any changes were made, press F4 to Save and Exit