GIANO Control Software

The GIANO control software is foreseen to run on a dedicated PC-Linux based workstation. This choice is considered robust and reliable compared to other existing PC operating systems. In particular, the use of Linux kernel 2.6 ensures some advantages in terms of general performance, software improvements, networking and system security.
In its general structure the GIANO software system can be subdivided into 3 main levels:

• Low-level software. This level is designed to handle all hardware-related functions and IR detector controls. It is physically split in two locations: one inside the GIANO workstation and the other into the embedded processor located at the focal plane electronics.
• High-level software. This level is intended to fulfil all astronomy-related tasks and also to act as an interface between the low-level software and the astronomer/operator. Hence, it includes several GUIs to provide a full control of all sub-systems.
• Scientific software. It includes the observing block preparation tools and the off-line data reduction pipeline.

Figure 16 shows the main architecture of the GIANO Control Software. Each software level deals with different aspects of the GIANO functionality and includes several blocks, which can be grouped as follows.

Figure 16: Main architecture of the GIANO control software.

• Detector Control Software (DCS): it manages the spectrometer array controllers. It is directly interfaced with the hardware and is responsible for the initial handling of the scientific data in real time.
• Instrument Control Software (ICS): this block manages the instrument status and also provides a GUI for monitoring purposes and interfaces with specific hardware modules, such as the detector, the sensors and the motors. Finally, it provides a list of FITS keywords describing the instrument status.
• Observation Software (OS): this branch coordinates TNG telemetry command variables, ICS and Flex (the TNG software for handling the observation blocks). It controls all the parameters needed to perform scientific exposures: instrument setup, initializations, array setup, calibration units setting and exposure time count-down. It also provides a GUI and additional frame processing facilities for quick look purposes.
• Observation Support Software (OSS): this task provides a tool for building off-line Observation Blocks during the phase I and phase II preparation. In its final version it will also include a web interface to the GIANO Exposure Time Calculator (ETC).
  The final structure and implementation of the OSS will be performed after the GIANO integration phase.
• Data Reduction software (DRS): it provides the off-line data reduction pipeline.

Each block is devoted to a particular job and is independent from the others. The advantage of this modular structure implies both reduced software complexity and easier maintenance. All interprocess communications are implemented by means of Unix-like sockets. The communication protocol has been designed to be as uniform as possible along all channels and consists of packets which are formed by a header containing essential information, among which the ``magic number'', a destination address, the packet description and reference number, a validity check and the related packet length. All data are in plain ASCII for easiness of debugging and maintenance.

In 2006 E. Rossetti developed some software modules both for GIANO-ICS and GIANO-OS:

• IS1: controls the temperature and pressure values inside the dewar;
• IS2 (cold movements): drives the movements of all stepper motors and switches; this version is optimized to perform laboratory tests (motor setup, compensations for play, alignments etc.);
• OS GUI: a prototype interface to test both the socket communication with the IR detector (simulated) and the acquisition of dummy fits file; the acquired file is displayed on an embedded DS9 panel.

A new release of IS1 is under development in order to extend the communication also with the GIANO Programmable Logic Controller (PLC).