The ESU brand offers 4 signal adapters for SwitchPilot, under part number 51809.
Presentation of the digital module under reference 51809,
This module is used to emit signal lights (which are usually fitted with LEDs).
Usually, "cathodes" are combined to reduce the number of wires, which is why the SwitchPilot couldn't control the signals. Thanks to this adapter, this problem is solved.