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LTSpice cursors on different runs of same parameter


New Member
I have a simple simulation which is working perfectly. I am running it with two separate values for the same component so as to produce two separate traces in the same pane. It works perfectly. I cannot find a way to attach a cursor to each of the traces so as to measure the static difference between their values. Is this possible? Thanks.


Well-Known Member
Most Helpful Member
Double click on the title of the trace to bring up two cursors.
Then use the Up/Dn arrow keys to move one of the cursors to the opposite trace, if necessary.


New Member
Fantastic Crutschow. I knew there had to be a simple way to do something so necessary. Thanks for sorting this for me.

Maybe I should put this into a separate query but it is sort of similar. Is there a way in formulaic calculations to define a particular value out of the same sort of trace setup based on specific and different trace matches?

By that I mean, let's say I have Vin and Vout traces and each one has two variants due to differing values for one of the components. I can set up "V(Vin) - V(Vout)" but that will give me a pair of results based on the pairs of traces matched according to the same component value. Can I specify something which defines "V(Vin): value 1 - V(Vout): value 2"?


Active Member

If you "step" a parameter value, then the step can be referenced in the waveform viewer.

For example, If you want to run three simulations each with a different value for capacitor C1 in a schematic,
Place a statement on the schematic like this:

.step param C list 1u 2u 3u

then for C1, specify the parameter {C} for the value of C1.

The result would be three simulation runs with C1 matching each of the values specified in the ".step" statement for each run.

Then, in the waveform viewer, you can have three plot panes each showing only the result for each step by specifying "@"
for the displayed value. So...if you have a voltage node labeled "out", Click the node so V(out) appears in the plot pane, then change it to read V(out)@1. That specifies you want the value of the first step. Open a new plot plane, click the "out" node again, then change V(out) to [email protected] to specify the second step, and so on...



New Member
That's another good step forward eTech. I'm up to speed and comfortable with the basic .step functionality of course but using the "@" designator is new to me. That's a great tip. I'll investigate whether this can be applied to the formula process to mix values from different steps in the same calculation. It may just be what I'm after.

Thanks all for your help. This is such a great tool, It just keeps on expanding beyond what you know and surprising you with how flexible it is.

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