Macros: Curs, CursDot

When Generator or Input is active, or when a file is open for viewing, two vertical cursor lines, one solid and one dotted, are superimposed over the trace. (Except in Sgram mode... see below.)

You can move the trace cursors by dragging with the mouse. From the keyboard, the unshifted left and right arrow keys move the solid cursor and the SHIFT+arrow keys move the dotted cursor. Because the same arrow keys are used by Windows to move the text cursor when an edit control has the keyboard focus, add an ALT key to move the trace cursors: ALT+arrows for solid, and ALT+SHIFT+arrows for dotted.

You can also move a trace cursor by directly entering the desired value in its X position readout. All readouts for the trace cursors appear in a group below the trace area, with the X values shown above the Y values for each cursor. The solid readouts are on the left, and the dotted readouts in the center. At the left end of each X readout is a small vertical bar showing a replica of the solid or dotted cursor, to remind you which is which.

Below that bar, at the left end of each Y readout, is a small square button in the color of the trace that the cursor refers to. When you have more than one active channel, all of the readouts default to the one with the highest priority: Inputs have priority over Outputs, and Left has priority over Right. The priority from highest to lowest is thus L.In, R.In, L.Out, R.Out. (This default channel is also the one whose values are used to label the Y axis.) If you click on the colored button, it will step through all the active channels from highest to lowest priority and wrap back to highest. This allows either cursor to read any channel.

The cursor readouts are not affected by the channel display buttons, as long as at least one channel is shown. This allows you to monitor a readout from one channel while viewing the waveform or Spectrum of another, without visual interference from the first.

Note that if you have both Generator and Input active, toggling Generator off will force any readouts that were showing output channels to show input channels. (And vice-versa if you instead toggle Input off.) The original Generator assignments will not be restored when you toggle it back on; you'll have to re-assign them with the readout buttons.

If you toggle both Generator and Input off, the most recent cursor assignments will be preserved (even though the readouts vanish when no channels are active), and will be available when the channels are toggled back on in the future... even if that is in another Daqarta session. But to take advantage of this retention, you must pay attention to the order you use when toggling Generator and Input. If you normally want to view only Input readouts (typical), always toggle Input on before Generator when starting up, and always toggle Input off after Generator when stopping. This way you avoid the Generator-only condition that would force the readouts to show only outputs.

The Spectrum dialog also has special cursor options for high-resolution interpolation of peaks, for automatic tracking of the highest peak, and for displaying the ratio of the two cursor frequencies.

By default, the Y readout values are smoothed to reduce jitter from noisy data. You can change the smoothing time constant or eliminate smoothing altogether via the Cursor TC (Time Constant) setting in the Preferences Dialog. If the TC is high and the true data changes suddenly, the cursor values may take a while to settle to the new value. You can reset both cursors to the current data values by hitting ALT+K. Moving an individual cursor also resets it to the new current value.

In Spectrogram ( Sgram) mode the cursors are not visible, but the readouts show the values that would be seen in Spectrum mode. (You can adjust them via the cursor keys or macros if you don't want to toggle back and forth to Spectrum mode.) The Sgram thus allows an overview of the signal in frequency and time, while the readouts still monitor real-time details.

Macro Notes:

Curs moves the solid cursor and CursDot moves the dotted cursor. Both commands operate similarly; the Curs command will be discussed here.

Curs=2m sets the solid cursor X position to 2 msec (or the closest sample to that) in waveform mode. Note that this command is relative to the current display mode: In Spectrum mode this same command will set 2 milliHertz, which will be rounded down to 0.

Alternatively, Curs=>1 moves the solid cursor one step to the right, and Curs=>-1 moves one step to the left, just like the right and left arrow keys.

The Curs command can only set X values that are within the displayable range, which is what you see with the X-Axis (eXpand) button off. If eXpand is on such that you see only a portion of the X axis, Curs can still set a position in the hidden part... the cursor just won't be seen until that portion of the axis is again visible.

In waveform mode the Trigger Delay setting affects the X-axis values that are shown; the Curs command can still only move to displayable positions. For example, if the normal X axis runs from 0 to 21.3 msec and you set Trigger Delay to 10 msec, the axis will run from 10 to 31.3 msec. Curs values will thus be limited to this range.

See also Cursor Delta Readouts, Cursor Sigma Readouts

• Back to Display Magnification
• Ahead to Cursor Delta Readouts
• Daqarta Help Contents
• Daqarta Help Index
• Daqarta Downloads
• Daqarta Home Page
• Purchase Daqarta

Questions? Comments? Contact us!