MI-3041 Data Acquisition
The MI-3041 Data Acquisition Software provides the capability to assign specific instruments to a particular user project, manage data acquisition configurations, collect data and store it on disk. The MI-3041 uses various software instrument drivers to control the assigned instrumentation.
This function allows the user to select what instruments are in use and define static parameters for those units that do not change from acquisition to acquisition. Each user project can use a different complement of instruments or static configurations.
This function collects and stores data according to an acquisition definition. It uses the current equipment configuration information and the acquisition definition to set up all instrumentation involved in the data collection. The Acquisition Manager creates and updates the real time confirmation plot shown during the acquisition. During acquisition, the user can change the data channel displayed and the scale of the confirmation plot. Rectangular, polar or color fill plot types are user selectable. The module stores the data on disk in the MI-3000 data file format.
Various data collection operations are supported:
- Data can be calibrated against an available standard gain horn data file as it is acquired
- Multi-frequency data at a single position
- Stepped or continuous scans and two-dimensional rasters of multi-frequency data
- Scans can be bi-directional or re-trace style
- 16 bits of digital control lines are available when a NAC is included. This allows management of a beam steering computer or other switching during an acquisition. The digital control can be interlaced with multiple frequencies during a single scan.
- A “Range Walk” acquisition for gated CW RCS configurations that maps the range in time. This acquisition is only available with the MI set of instrumentation.
- Where the position controller configuration allows, a continuous scan mode is available that continuously rotates the scan axis while the step axis is moved during a raster scan acquisition instead of halting the scan axis at the end of a scan to position the step axis. This can provide significant increases in range throughput.
- Through the use of Visual Basic® scripts, data can be collected at an arbitrary list of positions or non-uniform step angles.
- Real time position data can be recorded, for scan and step axes if the hardware supports it.
- Up to six axes of motion can be managed in a single acquisition. One axis can be the scan axis; one the primary step axis and four axes can be placed at a single or incremented location.
- When the position controller configuration allows, one axis can be configured to rotate continuously. This is useful for spinning linear axial ratio measurements.
- The beam peak can be automatically extracted from a scan and saved for use in future measurement configurations.
- When the position controller is an MI-4190 and the axis configuration allows, a master slave relationship between two axes can be used. The relationship is in the form of y = mx + b, where “y” is the location of the slave axis, “x” is the location of the master axis, “m” is the gear ratio between the axes and “b” is an offset between the axes.
- When the position controller is an MI-4190 and the axis configuration allows, the system can define a “virtual” axis that is a combination of motions of actual physical axes. The user can insert equations that define the virtual axis in relation to motion of the physical axes. The virtual axis is then treated like any other axis from a motion control standpoint.
- Data at a specific pointing angle can be collected prior to and after an acquisition. In addition, data at this pointing angle can be collected every n scans. This additional data can be used to take out thermal drift effects for long acquisition patterns.
- Data can be collected over a time interval of up to 8 hours at user selected increments. This data is treated as a single scan of data.
- When the position controller is an MI-4190, data can be collected in a manual mode where the user moves the scan axis by hand and the MI-3000 collects data over a designated angle interval until the user is satisfied with the data. The user may also clear out data that has been collected and start over as desired.
- A manual axis can be defined for axes that are not under computer control. These axes can be designated as scan axes during a measurement and the operator will be prompted to move the manual axis whenever movement of that axis is required during the measurement. A manual axis can also be used to collect a manual scan if a position display is associated with the manual axis.
- 16 bits of digital control lines are available when a DAC or MI-788 Networked Acquisition Controller is included. This allows management of a beam steering computer or other switching during an acquisition. The digital control can be interlaced with multiple frequencies during a single scan in a looped pattern. The “beam-frequency” list mode allows a specific beam state to be associated with each frequency.