I am using a .meas file to run after the simulation completes. As this has now grown considerably being able to use text substitution would help enormously but I can't figure out the syntax.?
For example the measurements are taken over a time period,i.e. "FROM 6.3e-3 TO 7.3e-3" so if I want to change this, I have to change every line that contains it.
It would better if I could set this once as a parameter and then use that parameter on each line.

I've tried various combinations of param, .param, traditional string commands but to no avail.
Is it possible to do this and if so, what is the correct syntax please and is there a cheat sheet anywhere?

Many thanks

Neil
?

Neil wrote, "I am using a .meas file to run after the simulation completes."

I just want to clarify one thing, which is probably obvious.? You run this .MEAS script from the waveform viewer, right?? (I ask because all .MEAS commands that are in the simulation itself, are executed only after the simulation itself has completed, even though LTspice says that it's still running.)

I'm not familiar with .MEAS scripts from the waveform viewer.? There is a Plot Defs file.? Have you been editing that file to include your parameter definitions?? When you refer to the parameters, are you using {curly braces} around them?? This might not help because my experience there is approximately zero.

Andy

Hello Neil

I am using a .meas file to run after the simulation completes. As this has
now grown considerably being able to use text substitution would help
enormously but I can't figure out the syntax.
For example the measurements are taken over a time period,i.e. "FROM 6.3e-3
TO 7.3e-3" so if I want to change this, I have to change every line that
contains it.
It would better if I could set this once as a parameter and then use that
parameter on each line.

I've tried various combinations of param, .param, traditional string
commands but to no avail.
Is it possible to do this and if so, what is the correct syntax please and
is there a cheat sheet anywhere?

If I understand correctly, you want something like this:

.meas t1 param 6.3m
.meas t2 param 7.3m
.meas a avg v(x) from t1 to t2
.meas b rms i(v1) from t1 to t2
.
.
.

Alternatively, you can define t1 and t2 as parameters:

.param t1=6.3m t2=7.3m

but then you'd have to re-run the simulation so that the .PARAMs are
recalculated. With .MEAS they will be available only inside the .MEAS
script.

Looking at the values for t1 and t2 (as you exemplified), maybe you
need these to be calculated for (say) a period of some frequency. Then
you can more easily define them as:

.meas freq param 1k
.meas delay param 0.3/f
.meas t1 param 6/f+delay
.meas t2 param 7/f+delay

If the frequency, itself, is a variable to be determined from
measurements, then you could also use this:

.meas tmp1 find time when v(x)=0 cross=13 ; or some other trigger
.meas tmp2 find time when v(x)=0 cross=15
.meas f param 1/(tmp2-tmp1)
; and now continue with t1, t2, etc

--
Vlad
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