With automatic pre-signal setups enabled (see Pre-signals), all signal blocks that satisfy the following conditions will be converted to pre-signal blocks:
- At least one one-way signal going in
- At least two two-way signals
- At least one of these two-way signals leads to a block with another one-way signal going out, or an end-of-line.
If these three conditions are met, the one-way signals from condition 1 will be turned into a pre-signal, and the two-way signal(s) satisfying condition 3 will be turned into pre-signal exits. All other signals are left as they are, in particular, non-conforming two-way signals will not be converted.