Measurement Computing DaqView for DaqTemp Applications - Manual (Page 19)

DaqTemp Applications 967996 1108-0902, rev 2.0 DaqView, pg. 17
The Copy Waves and Paste Waves buttons use the system clipboard to post and receive waveform data
from all DAC channels. The data formats are identical to the Save and Load operations. Copy and Paste are
recommended for use with spreadsheets to numerically inspect and/or modify waveforms. Waveforms can
also be copied and pasted from the popup menu that is displayed when the mouse is right clicked over the
Waveform display. The waveform selected in the DAC selection listbox is the target of the Cut or Paste.
If multiple channels of data are on the clipboard, you can select the one that you want to paste into the
selected DAC channel.
The size of the memory buffer allocated for each DAC channel is determined by the number of updates that
you specify. Different Daq devices have different limits on the maximum updates that can be specified.
You can select one of three clock sources to pace the DAC output. The three options are as follows:
• DAC Pacer with a rate set in the Sample Update Rate field. When using the DAC pacer, the
Update Rate field controls the speed at which the DAC is updated.
• Acq Pacer, the clock used by the analog input section of the DaqBoard. Using the Acq pacer
clock synchronizes the update of the DAC output with the analog input data collection.
• External TTL. Update rate is controlled by the rate of the clock signal applied to the external
input pin.
Note: If the DAC Pacer clock is selected, you must enter the update rate that paces the DAC outputs.
The selection for the DAC channel for which you want to create a waveform, is made in the DAC selection
listbox,. From the same listbox you can control the channel's output by clicking the checkbox on or off.
Note that DaqTemp7A, having two DACs allows for two channels to be selected. DaqTemp14A allows for
up to 4 DAC analog output channels to be selected. The non-“A” series (DaqTemp7 and DaqTemp14)
have no DACs.
In the Waveform selection box, you can select a standard function generator waveform (sine, square,
triangle, sawtooth) or an arbitrary freehand drawing. In arbitrary mode, move the mouse to the waveform
window and draw a waveform using the left mouse button. The drawn waveform will be loaded into the
channel selected in the DAC channel listbox. You can also create a waveform by right clicking the mouse
with the cursor over the waveform window. Select the waveform type from the resulting popup menu.
Repeat this process for each channel in the DAC selection listbox.
To start the waveforms playing on the DACs, click the Start Waveforms button.
Auto Scale Waveform
DaqView provides an easy method to determine the upper and lower extents of the selected DAC
waveform. Simply right click the mouse over the Waveform display, and select the Auto Scale item from
the popup menu. DaqView scans the waveform for the highest and lowest values, then sets the upper and
lower waveform range fields to these values. This causes the waveform to be displayed full scale within
the waveform display.
This is useful if the waveform is off scale on the high or low end (indicated by the range input field color set
to red) and you want to bring it back to a full scale view.
Auto Fit Waveform
The DaqView Auto Fit feature is similar to Auto Scale. However, Auto Fit causes the data to be re-scaled
so it fits full scale in the range defined by the values in the upper and lower range input fields.
Note: For some Daq hardware, when hardware triggering has been selected to trigger an acquisition, DAC1
is used internally to supply the desired threshold voltage. In this case, CH 1 is not available for
waveform output. The Copy Waves and Paste Waves buttons use the system clipboard to post and
receive waveform data. The data formats are identical to the Save and Load operations. Copy and
Paste are recommended for use with spreadsheets to numerically inspect and/or modify waveforms.
To start the waveforms playing on the DACs, click the Start Waveforms button.
Note: When the analog input section is set for analog input triggering, DAC1 is used internally to supply the
desired threshold voltage. In this case, DAC1 is not available for waveform output.