1.8. Avantes AvaSpec Spectrometer

Summary:

Avantes AvaSpec

Type:

DataIO

License:

LGPL

Platforms:

Windows, Linux ready but not tested

Devices:

Avantes AvaSpec Spectrometer

Author:

M. Gronle, R. Hahn, W. Lyda, ITO, University Stuttgart

1.8.1. Overview

This DLL integrates the Avantis AvantesAvaSpec spectrometer series into itom. It uses a low-level libusb connection to communicate with the devices and has been tested with the following spectrometers: * AvaSpec 3468 USB-Spectrometer * AvaSpec 2048 USB-Spectrometer * AvaSpec-ULS2048CL-EVO USB3-Spectrometer.

1.8.2. Initialization

The following parameters are mandatory or optional for initializing an instance of this plugin:

  • VendorID: int

    VendorID of spectrometer, 0x1992 for AvaSpec-3648, 0x471 for AvaSpec-ULS3648…

    Value range: [0x0, inf], Default: 0x1992

  • ProductID: int

    ProductID of spectrometer, 0x0667 for spectrometer

    Value range: [0x0, inf], Default: 0x667

  • isUSB3: int, optional

    Indicates if the device is a USB3 device

    Value range: [0, 1], Default: 0

1.8.3. Parameters

An instance of this plugin has the following internal parameters:

average: {int}

Number of averages for every frame

bpp: {int}, read-only

Bit depth. 16 (uint16), if single acquisition. 32 (float32), if averaging.

integration_time: {float}

Integration time of CCD programmed in s, some devices do not accept the full range of allowed values (see AvaSpec for real minimum value of your device).

lambda_coeffs: {seq. of float}, read-only

Coefficients for polynom that determines lambda_table (lambda_table[idx] = c[0] + c[1]*idx + c[2]*idx^2 + … + c[4]*idx^4)

lambda_table: {seq. of float}, read-only

Vector with the wavelength of all active pixels

name: {str}, read-only

plugin name

roi: {int rect [x0,y0,width,height]}

ROI (x,y,width,height)

serial_number: {str}, read-only

Serial number of spectrometer. Same as identifier.

sizex: {int}, read-only

current width of ROI

sizey: {int}, read-only

current height

detector_name: {str}, read-only

Name of the detector.

dark_correction: {int}

Dark correction mode. See section below.

1.8.4. Timestamp

Every acquired image will have a tag ‘timestamp’ defined. It contains the timestamp of the acquisition in seconds since the startup of the spectrometer.

1.8.5. Vendor and Product ID

If the vendor or product ID is unknown, open the libUsb plugin and select the optional parameter “print info of all devices”. This will give you a list of all usb devices connectable with libUSB.

1.8.6. Dark correction

Some spectrometers have more pixels on the sensor than are used for the signal generation. These, covered and hence dark pixels, can be used for a dark correction. There are three types of dark correction (parameter dark_correction):

  • Off (0): No dark correction is applied, if the sensor is recognized to have such dark pixels, a tag ‘dark’ is created that contains the mean value of all dark pixels. If no averaging is enabled, the output format of the dataObject is uint16, else float32. Sensors, that don’t have dark pixels can only be operated in this mode.

  • Static (1): The mean value of all dark pixels is subtracted from all pixels. The output format is float32 always (negative values might occur).

  • Dynamic (2): Only choose this mode, if the software AvaSpec provides dynamic dark correction for the sensor (see sensor configuration >> checkbox ‘dynamic dark correction’ must be enabled. In this case, odd and even pixels have different dark correction values (they are probably read by different electronics). Choose this mode to subtract different mean values for even and odd pixels. The tag ‘dark’ still contains the mean of both mean values (0.5 * (mean_even + mean_odd)).

1.8.7. Changelog

  • itom setup 3.1.0: This plugin has been compiled using the libUSB Plugin

  • itom setup 4.1.0: This plugin has been compiled using the libUSB Plugin