Osiris Data Acquisition System DAS

The DAS is based on a classical ARC-GenII controller, using a timing board with parallel cable linked to a digital PMC-type commercial frame grabber plugged into a VME-crate running VxWorks OS (see Figures 1 and 2). The cable supports very high data rates and is presently implemented at 6.25 Mpixels/s (only 4 MHz is needed in a 4-channel configuration). A fiber optics link has been added. More details about this configuration can be found in Joven, et al. [2]. Table 4 summarizes the main elements of the OSIRIS DAS.

Table 4. OSIRIS Data Acquisition System

Element

Model

Mosaic

Two - E2V44-82 back-illuminated CCDs (4096x4102 pixels)

Controller

Modified ARC-Gen II (San Diego, USA)

Output

RS422 to fiber optics (Arvoo, Netherlands)

Interface

PMC-digital frame grabber (Datacell, UK)

Operating system

VxWorks real time operating system (Wind River, USA)

Shutter

Bonn University (Germany)

Cryostat

LN2-based (TTM, Valencia, Spain)

Control crate

VME-bus (Wiener, Germany) with MVME2400/5100 Motorola CPUs

Communication

PMC Dual-Giga ethernet

Figure 1. (left) OSIRIS DAS including a couple of eng-E2V44.82 CCDs in the test bench. (right) Main control crate.
Figure 2. (left) One of the OSIRIS control panels of the DAS, included in the Inspector-GCS and showing a Python Shell for scripting. (right) VISADO Program, real time JSkyCat-based image visualization application.

2.2 Other Related OSIRIS Subsystems

The OSIRIS control architecture allows the coordination and synchronization of critical operations (for example, charge shuffling and wavelength tuning) with real time constraints (see Figures 3 and 4).

Figure 3. (left) Filter wheels. They include pupil masks, conventional filters and light dispersive elements (grisms). (right) Main elements mounted in the last wheel are the two tunable filters, which convert OSIRIS into a very versatile instrument. Development of the four wheels has been carried out by NTE (Barcelona, Spain). Tunable filters are made by ICOS (London, UK), with a new entire FPGA-based control developed by the OSIRIS team (see Gigante, et al. [3]).

Figure 3. (left) Filter wheels. They include pupil masks, conventional filters and light dispersive elements (grisms). (right) Main elements mounted in the last wheel are the two tunable filters, which convert OSIRIS into a very versatile instrument. Development of the four wheels has been carried out by NTE (Barcelona, Spain). Tunable filters are made by ICOS (London, UK), with a new entire FPGA-based control developed by the OSIRIS team (see Gigante, et al. [3]).

Figure 4. (left) Mask loader, including control, mounted at the test bench in the IAC facilities. All the mechanisms are driven by DC servo motors (Parker). (right) Collimator frame support. The collimator mirror has been manufactured by SESO (France), and its support and micro-actuators by CSEM (Switzerland).

Figure 4. (left) Mask loader, including control, mounted at the test bench in the IAC facilities. All the mechanisms are driven by DC servo motors (Parker). (right) Collimator frame support. The collimator mirror has been manufactured by SESO (France), and its support and micro-actuators by CSEM (Switzerland).

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