===== POOLs =====

Pools are used in the [[en:traffic:timetable:start|timetable]] of [[en:traffic:start|Traffic Screensaver]] since version 4.2 to simplify the use of [[en:traffic:timetable:motion:start|vehicle movements]]. They make it possible to use the same movement lines group by group several times in the same timetable without having to write them several times.

==== Definition of POOLs ====

To define a POOL, one or more lines of movement are framed at the beginning by a line beginning with $POOL and naming the POOL with //N=// and ending with the expression $ENDPOOL.

<code>$POOL N=movements

<Motion lines>

$ENDPOOL</code>

This defines a POOL named "Movements".

==== Using POOLs ====

Once you have defined a POOL, you can use it as often as you want and almost anywhere on the timetable - of course only by definition - by specifying //POOL=// and the name of the POOL.

<code>POOL=movements</code>

Even POOLs can be manipulated in the probability of their occurrence.

<code>POOL=1:Pool1|9:Pool2</code>

causes ten pool POOLs to be one pool1 and the other nine pool2.

==== nesting ====

POOLs can not be nested, so enter them in other POOLs. You can only include motion lines. In the case of nesting, Traffic issues an error message.