Hi Miguel,

That really is an either / or question. You can use the contact rails for switching purposes. In that case you use the contact to close an electrical circuit when a train moves over it. The circuit can switch something through a relay or directly, for instance a turnout motor. Keep in mind that anything that is switched directly should be able to withstand continuous powering, in case the train stops on the contact. Also, everything is switched with current taken from your loco control, be it a transformer when running analog or a digital control station. However when running digital this is not a recommended practice.

Alternatively, you run a single wire from the contact rail to a S88 module, which must be hooked up to a digital system with either a readout for s88´s or with computer control. In that case the signal (mass detection) is used to identify sections of track on your layout that are occupied by a train. When using computer control or an advanced digital system like CS2 that information can be used to follow a train around the layout and to set turnouts and signals in accordance with planned routes around the layout, just as it is done in real life. Here is an example of such a system: Click here.

Regards, Robert