Automatic signals come in two forms.
A signal that is normally uncontrolled by the signaller but displays an aspect dependent on the state of the track and signals in front of it. The signal will normally have a notice plate on it; in SimSig this is shown by a small line under the signal's aspect.
Technically the plate indicates the signal is "passable" - it can be passed at danger under certain circumstances. Usually auto signals are passable and vice versa, but some auto signals (perhaps those approaching a viaduct or tunnel) are not passable and so do not carry the special plate (and, in SimSig, don't have the small line). Rarer, but technically possible, is a controlled signal that is passable.
Some Automatic signals have red ‘E’ or ‘R’ emergency replacement button which will turn the signal red in an emergency. In SimSig, Right Clicking the button will set the signal back to red, a Left click will restore the signal to automatic working. (Note: Right clicks cancels an action ie cancels the route; Left click sets a route ie restores Auto working)
The other type of automatic signal is the controlled one where the signaller has the option of setting it to automatic by the use of a button (technically this is a "controlled signal working automatically"). On SimSig this is a blue ‘A’ button beside the signal.
Note that not all routes from these signals will necessarily have the ability to be set to automatic. In some places the signal can only be set to automatic working once it has cleared to yellow or better.
Last edited by clive on 22/02/2019 at 15:29