About the DCL - Systems Description

CCD System Configuration (UVIS)
Infrared System Configuration (NIR)
DCL Software System Description

Overview

The DCL contains hardware and software elements designed to simplify the data acquisition process on up to 4 independent (2-optical and 2-IR) systems simultaneously. The top level Graphical User Interface (GUI) is Image Display Language (IDL) driven which interfaces with:

1. The San Diego State University developed CCD/IR control software (CCDTool)
2. The San Diego State University Generation II System Controller (SDSU Gen II)
3. The detector support hardware
4. The Labview monitoring of the environment and control of lab equipment
5. The monochromator assy (via Labview)
6. The DCL database
7. The DCL website

In addition to the device characterization/optimization capabilities, the DCL is equipped for autonomous data acquisition from both the device under test, and from the associated state of the lab environment. This capability provides a complete inter/intra experiment database allowing for efficient post-test analysis with quick turn-around anomaly resolution.

The complete DCL system configuration for controlling optical or CCD detector arrays is shown schematically here. The complete DCL system configuration for controlling IR detector arrays is shown schematically here.

CCD System Configuration (UVIS)

The major system components for the CCD controller system are listed below, with a short description of each. In addition to the controller housing and the external DC power supply, the system is comprised of the following:

1. Utility board - provides integration (exposure) timing, shutter control, detector temperature control, system power supply limit checking and enable control, and temperature monitoring.
2. Timing board - communicates with the Sun workstation via the S-Bus interface board over fiber optic cable, providing digital timing (sequencing) signals to control the CCD array.
3. Clock driver board - translates digital timing signals from the sequencer to controlled voltage levels for driving array clock lines.
4. CCD video processor boards (2) - amplifies and digitizes video signals from the CCD arrays and provides the DC bias voltages to the CCD arrays.
5. S-Bus interface board - interfaces the timing board via fiber optics to the Sun workstation.
6. Power control board - shares responsibility with the utility board in performing a power up system voltage limit check, and if within bounds, slowly ramps up analog power to the other controller system boards.

Infrared System Configuration (NIR)

Below are listed the major system components for the IR controller system, with a short description of each. The IR controller design is based on the SDSU Gen II controller without the utility board, and employs custom IR video processing boards. In addition to the controller housing, the external DC power supply and the Lakeshore temperature controller, the system is comprised of the following:

1. Timing board - communicates with the Sun workstation S-Bus interface board over fiber optic cable, provides digital timing (sequencing) signals for controlling the array, and performs utility board functionality since the utility board does not exist in the IR controller.
2. Clock driver board - translates digital timing signals from the timing board sequencer to controlled voltage levels for driving array clock lines.
3. IR video processor boards (2) - amplifies and digitizes video signals from the IR arrays and provides the DC bias voltages to the IR arrays.
4. S-Bus interface board - interfaces the timing board via fiber optics to the Sun workstation.
5. Power control board - shares responsibility with the timing board in performing a power up system voltage limit check, and if within bounds, slowly ramps up analog power to the other controller system boards.

DCL Software System Description

The top level DCL GUI on the Sun host workstation is written in IDL widgets, spawning to a C library when necessary. The GUI communicates with the Labview drivers/virtual instruments through TCP socket programs called from IDL. The interface also runs the data acquisition software routines from CCD Tool for both optical and IR systems. The IDL GUI can additionally access widget-based analysis tools. When anomalous environmental conditions are reported by the Labview system during or between experiments, IDL will flag and time correlate the event for placement into the associated FITS header file. This provides more efficient ex-post-facto anomaly investigation for the user.

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