I have a SV411KUSB connected to 3 PCs. On my main PC I use Oracle’s Virtualbox running a number of Linux installs (3). For some time now I have had issues when switching between the different Virtualbox GUEST environments. When I do so, the SV411KUSB switches to another PC. It didn’t always do it so it has taken me some time to work out exactly what was going on.
The issue was with an interaction with the “NUM LOCK” state of the HOST and GUEST machines. When switching between HOST and the multiple GUESTs if the NUM LOCK state was different, the SV411KUSB took this as me having pressed NUMLOCK twice and so switched it’s inputs!!
Extremely irritating - manually switch back to main PC, switch to another GUEST and switches back to another PC again. As the 2nd PC was not powered on I could not use hot keys to switch back but had to manually press the button on the KVM, repeating over and over……..
It was difficult to ensure that the NUMLOCK state was always the same between the different environments and it does not seem possible to disable the NUMLOCK, NUMLOCK switching function on the KVM but I found a hidden setting in Virtualbox that eliminates the issue by using the VBoxmanage utility
From The VirtualBox website
To manage Num Lock in VirtualBox, you can disable keyboard indicator synchronization to prevent the host’s Num Lock state from toggling the guest’s state. Using a command prompt, run: VBoxManage setextradata "VM Name" GUI/HidLedsSync "0". This prevents synchronization, allowing the guest OS (e.g., Windows/Linux) to manage its own Num Lock status independently.
I have set this on the 3 Linux environments and now I can switch between the GUESTS and the SV411KUSB does NOT randomly trigger.
I hope this is helpful for anyone else experiencing this issue.