Detect which buttons (on the display) of the controller (PacDrive LMC Pro/Pro2, PacDrive LMC Eco) are activated.
The function returns the status of the display buttons. The status can be retrieved from the least significant bits of iq_byButtonsActive. If a bit is set, the button is being activated.
Bit#0: Button "up" (left button)
Bit#1: Button "Down" (right-hand button)
Bit#2: Button "Enter" (button in the middle)
"ButtonsActive" outputs the information on the buttons that are activated.