Signal Selector

The Signal Selector is an automation building used to route one input signal to its output based on control input(s). It is part of the automation system and can work with either single signals or automation ribbons, making it useful for choosing between multiple logic states without rebuilding an entire circuit.

When used with a single wire, the Signal Selector passes through the selected input signal directly. When used with an automation ribbon, the exact behavior depends on bit depth: if both the input and output are ribbons, the selected ribbon is copied bit-for-bit; if a single wire is connected to a ribbon output, only the first bit is set to the chosen signal and the remaining bits are red; if a ribbon is connected to a single-wire output, only the first bit of the selected input is used. If any non-first bits of a ribbon output are not red when they should be, the corresponding output wire can take signal overload damage.

The building has two control inputs. With single wires, they behave normally. With ribbons, only the first bit is read, so the control input is considered green only when bit 1 is green. This makes the building sensitive to ribbon layout in a way that is easy to miss when designing compact automation.

Its animation can also be misleading: if any bit in the selected input is green, the building graphic shows the transmitted signal as green. Only when every bit in the input is red does the graphic show red. That means the displayed state and the actual output state do not always match.

A few practical notes are worth keeping in mind:

• The Signal Selector can be used to choose between multiple candidate signals without chaining many logic buildings.
• When connected to ribbons, pay close attention to bit 1 on both the selected input and the control input.
• The building’s display does not always reflect the full ribbon output, so verify circuit behavior with the actual wire state rather than the animation alone.