Re: .MEAS syntax with variable parameters
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Yeah, with or without parens, it Fails.
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Nice feature when editing a ,MEAS (after a Run), there¡¯s a Test button that executes the measurements on the last data set.
Click. Fails!
Edit. Click. Data displayed
Even for .stepped runs, which returns the whole list(s)!
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From: [email protected] <[email protected]>
On Behalf Of John Woodgate
Sent: Friday, March 28, 2025 2:14 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] .MEAS syntax with variable parameters
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I'm no expert in this area, but expressions within { } are evaluated before simulation, which is not what you want, of course. What if you use ordinary ( ) instead?
On 2025-03-28 20:16, Bell, Dave via groups.io wrote:
I¡¯m frustrated by failure of a time measurement I¡¯m trying to make.
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My circuit generates a pulse train with parameterized width, Pw.
I want to measure a delay, from a rising edge of one node, N0, to the next rising edge of another node, Nx.
Due to a filter action, the amplitude of V(nx) is dependent upon a resistor whose value is stepped, from run to run.
Because of that, I want to make the trigger (target) amplitude a variable, say 90% of the MAX() amplitude of node Nx.
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- .meas VNx MAX V(Nx) FROM {5*Pw} TO {25*Pw}
- .meas T1 TRIG V(N0)=2.25 TD=3u RISE=1 TARG V(Nx)=250m TD=3u RISE=1
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Measurement 1 correctly returns a peak value from say 0.5V to 4.5V.
Measurement 2 returns a time that¡¯s too close to the stat of Rise, instead of near the peak level.
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T1 Fails if I use this instead:
- .meas T1 TRIG V(N0)=2.25 TD=3u RISE=1 TARG V(Nx)={0.9*VNx} TD=3u RISE=1
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Help??
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Dave
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--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion
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Bell, Dave