Use the “DC/AC/GD” switches to select the input coupling of a channel.
In position “AC” (=alternating current coupling) the signal is RC-coupled. Its DC component is filtered. In position “DC” (=direct current coupling) the DC components are not filtered.
The position “GD” (=”Ground”) shortens the signal input connector, which results in a horizontal line on the screen as between ground and signal not voltage potential remains (in the simulation this always equals 0 V input level).
While theoretically any type of signal can be loaded into a virtual cable in the simulation software, this simulation is limited to sinus signals. The switch position “DC” therefor generates the same output as the switch position “AC”.