VKB-SIM

Let me ask this another way.
What is the left red LED above the F buttons for?

I use this stick for IL-2 and I understand that all the controls have 2 modes. In other words I can use SW-1 for landing gear and then switch modes and use it for say...canopy open-close. Question is....What key or binding makes the switch between modes? I assume that is why there is a blue LED and ...