The “invert” button determines which logic level corresponds to the active state of the signal. However, there is an exception for EMUS G1 Control Unit speed sensor input (SPEED IN), if it is mapped with its default function, the “invert” parameter changes which edge is used to count the pulses of the speed signal. If not inverted on the rising edge if inverted on the falling edge. Otherwise, the meaning is the same as for general-purpose inputs.