Drawing Selection Rectangles

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Drawing Selection Rectangles

In WinDaq Acquisition, you can draw a graphic selection rectangle and just a plain selection rectangle. A graphic selection rectangle is used to copy the graphics bounded by the graphic selection rectangle (drawn with the mouse) to the clipboard. The selection rectangle is used with the mouse just to offset and/or scale a waveform.

Both rectangles are drawn the same way, only the graphic selection rectangle is created with the right mouse button while the selection rectangle is created with the left mouse button.

A graphic selection rectangle is drawn by positioning the mouse pointer anywhere in the waveform strip area and dragging with the right mouse button until the rectangle encloses the area you wish to copy to the clipboard. When the mouse button is released, the rectangle remains fixed in size. You can now choose Copy from the Edit menu to copy the enclosed graphics to the clipboard.

A selection rectangle is drawn by positioning the mouse pointer anywhere in the waveform strip area and dragging with the left mouse button until the rectangle reaches the desired size. When the mouse button is released, the rectangle remains fixed in size. The following examples illustrate how the selection rectangle can be used in typical offsetting and scaling operations.

Offsetting a Specified Channel’s Waveform

1. The original waveform. The object is to offset the waveform from its current position to a position centered on the screen. Note that the “1=1” annotation in the left annotation margin is highlighted, indicating window 1 is enabled for adjustments.

2. Drag the left mouse button to draw a selection rectangle. The size (and placement) of the rectangle is immaterial. In this example, it was drawn to approximate the vertical limits of the waveform so it could be accurately centered at the center of the screen. Note that the rectangle remains fixed in size when the left mouse button is released.

3. With the mouse pointer positioned inside the selection rectangle, drag the rectangle to achieve the desired offset (in this example, vertically centered at the center of the screen).

4. The offset waveform. When the left mouse button was released, the waveform was vertically offset by the amount the rectangle was dragged (within the limits of the A/D converter’s dynamic range). Note the waveform’s numerical values in the left annotation margin reflect the new position.

Scaling a Specified Channel’s Waveform

1. The original waveform. The object is to scale a small section of waveform so it fills the entire strip area, thus allowing the small section to be examined in greater detail. Again note that the “1=1” annotation in the left annotation margin is highlighted, indicating window 1 is enabled for adjustments.

2. Drag the left mouse button to draw a selection rectangle. Once again, the size of the rectangle is immaterial. In this example, it was drawn on the very tip of the waveform because this is the area of interest that we would like to examine in greater detail. Note that the rectangle remains fixed in size when the left mouse button is released.

3. The scaled waveform, accomplished by clicking the left mouse button in the left annotation margin. The contents of the selection rectangle have been scaled to fill the entire waveform strip area.

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