The traffic control system ILTIS

Operators at Altstetten no longer give commands to interlocking plants directly. Instead, they command the stations within the territory of the Altstetten control center by means of the ILTIS traffic control system.

Above the interlocking plant, the next-highest level in the processes for the daily control of rail traffic is the traffic control system ILTIS.

Operators no longer give commands to the SIMIC-C interlocking at Altstetten station directly. Instead, operators command it and the interlocking plants at the other stations within the territory of the Altstetten traffic control center by means of the ILTIS traffic control system (Siemens Integriertes Leittechnik-System - see the relevant German-language page in the Siemens Switzerland web site).

ILTIS is fully graphic-based. The operator issues commands by means of a mouse only, not by means of typed codes as in the underlying SIMIS-C interlocking. Here is what the operator sees on the ILTIS system (in the overview display or Übersichtsbild) for Altstetten station:

(Click on the image for a larger
version and more information.)

The user can drag a window not just within one screen, but also - with one extra command - over to another screen. Using ILTIS, the operator can set up, on a one-time basis, train routings (Fahrstrassen) for trains and close gates at grade crossings (places when a road crosses the tracks).

A common application is to allow a train to reverse direction (for example, in a situation with many late trains), or even in normal times for switching movements and the movement of suburban trainsets onto garage tracks.

These are examples of routings for switching moves (Rangierfahrstrassen) that cannot be programmed in the real-time train-routing system.

In normal operation using ILTIS, the operator can cancel a train path, but to do so, he must "open" the station's interlocking in a separate closeup window, re-set the entry signal to stop on an emergency basis (Signal auf Nothalt stellen) and cancel each track section of the train path individually.