How to run .meas script?

QSPICE
1

I can’t figure out how to run a .measure script. Is this supported in Qspice?

2

You can just put them on the schematic. The post processor is run after the simulation.

Alternatively, the Waveform Viewer has the top level menu command. File=>Run a .meas script.

There are several .meas statements in the example schematics available under File=>Open Demo…

1 Like
3

Yes, meas script works fine when included in the simulation, however cannot get it to work when using the same command from the waveform viewer top level.
File=>run a meas script. The meas.txt or test.meas is in the same directory as the *.qraw file. The measurement window opens but stays empty. I just copied the meas statement from the schematic and pasted in the "new ASCII File "from the file menu . Saved it. and run it. does not work that way.

4

Beware that the first line of your script must be a comment line.

Since Run a .meas script supports running SPICE netlists by reading only their .meas statements—and the first line of a SPICE netlist must be a comment or it will be ignored—the first line of your .meas script needs to follow netlist syntax.

*
.meas Vx-rms RMS V(x)
.meas Vy-rms RMS V(y)
.meas Vz-rms RMS V(z)

In addition, in the waveform viewer, if you move your mouse cursor over a trace label and hold Ctrl + right-click, you can access some basic measurements.

5

Yes it works. Was not aware that the first is ignored.
I was aware of Ctrl + right-click, to access some basic measurements.
Thanks, for the extra information.
Leaves me with one extra question, When the measurement is added in schematic, the results are shown in the post Process output window.
That give me the option with right click: Plot these measurements.
This is not available in the measurement window that appears with running the script.
Any simple way to plot the measured results?

6

Oh… the Plot these Measurements option in the Schematic Output Window generates a .meas waveform file ([name].meas.qraw), which allows you to view a plot.

However, running the script for .meas in the Waveform Window does not perform that operation. You might consider emailing Mike to submit a request for his review. I suggest waiting until you see QSpice get its next update before sending such a request. Currently, he may be out of the office or busy with other tasks—that is just my guess.