Creating and Using Math Waveforms
CSA7000B Series & TDS7000B Series Instruments User Manual
3- 171
H Clearing the data in a waveform source causes a baseline (ground) to be
delivered to any math waveform that includes that source until the source
receives new data.
Expression Syntax. You build math waveforms using the Define/Edit Expression
control window. To help you create valid math waveforms, this window blocks
most illegal entries by disabling any window element that would create an
invalid entry in the math waveform expression.
The syntax that follows describes valid math expressions, which can be quite
complex (in excess of 100 characters long):
<MathWaveform> := <Expression>
<Expression> := <UnaryExpression> | <BinaryExpression>
<UnaryExpression> := <UnaryOperator> ( <Term> )
| <UnaryOperator> ( <Expression> )
<BinaryExpression> := <Term> <Bina ryOperator> <Te rm> | <Scalar>
<BinaryOperator> <Term> | <Term> <BinaryOperator> <Scalar>
<Term> := <Waveform> | ( <Expression> )
<Scalar> := <Integer> | <Float> | <Meas--Result> | <Variable>
<Waveform> := <ChannelWaveform> | <ReferenceWaveform> | <MathWaveform>
<ChannelWaveform> := Ch1 | Ch2 | Ch3 | Ch4
<ReferenceWaveform> := Ref1 | Ref2 | Ref3 | Ref4
<MathWaveform> := Math1 | Math2 | Math3 | Math4
<UnaryOpera tor> := Average | Integral | Derivative | Invert | Sqrt | Exp
|log10|loge|Fabs|Sin|Min|Max|Ceil|Cos|Tan
|ASin|Sinh|ACos|Cosh|ATan|Tanh|Floor
| Spectral Magnitude | Spectral Phase | Spectral Real | Spectral Imag
<BinaryOperator>:=+|--|/|*|==|!=|<|<=|>|>=|CHS|EXX
The logical opera tors generate a vector that is all 0.0 or 1.0. Operators && and
| | are not provided, but if x and y are e xpressions equal to 0 or 1, then x*y is
the same as x&&y and (x+y)>0.99 is the same as x| |y.
<Meas--Result> := meas1 | meas2 | meas3 | meas4 | meas5 | meas6 | meas7 | meas8
<Variable> :>= VAR1 | VAR2 | VAR3 | VAR4 | VAR5 | VAR6 | VAR7 | VAR8 |
Waveform Differentiation. The math capabilities of the instrument include
waveform differentiation. This allows you to display a derivative math waveform
that indicates the instantaneous rate of change of the waveform acquired.