Actors

All actors interacting with the ATCS are shown in the top-level context diagram in [Figure 3] in this chapter.

Human and High-level actors

The following human actors are directly interacting with the AT Control System with increasing privileges:

The VLTI Control System-ISS is a non-human actor that interacts with the AT Control System at Operator level.

An observer/instrument is NOT allowed to interact directly with the ATCS, they have to go through ISS. Nevertheless for Maintenance/Installation/Tuning the AT can be used as a standalone system also for observing.

AT Sub-Systems

The scope of the Auxiliary Telescope Control Software (ATCS) concerns the control of all the sub-systems listed in FunctionalSpec - SubsystemSoftware. They are therefore considered actors in the Use Cases.

These actors are mainly passively interacting with the AT Control System in the exception that:

General Observatory Information

In addition, the following VLT Sub-Systems providing general services at site level are interacting (mainly passively, i.e. providing a service as a secondary Actor) with ATCS: