Resources Used In The Expressions - Keysight B2980B Series User Manual

Function Details
Math Expression
VARALPHA Calculates varistor alpha using the following formula.
VARALPHA = log(CURR[c][1] / CURR[c][0]) / log(VOLT[c][1] / VOLT[c][0])
where, CURR[c][0] and VOLT[c][0] are the measurement data at a point on a
varistor's non-linear I-V characteristics curve, and CURR[c][1] and VOLT[c][1] are
the data at the another point.

Resources Used in the Expressions

The following resources can be used in user-defined math expressions.
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•
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226
Reserved variables
The variables listed in
data of voltage source output.
Scalar variable is used for spot measurement data.
Vector (array) variable is used for sweep measurement data.
Math operators
The following operators are available.
Arithmetic operators: , , *, /, ^, see
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Elementary functions: ln, log, sin, cos, tan, exp
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The functions log and ln perform the operation after calculating the absolute
value. So if a negative value is specified, they do not cause an error but
calculate as a positive value. For example, log(10) results in log(10)=1.
Math variables
You can use maximum 32 variables in the math expressions. To use the math
variables, see "Math Variable Dialog Box" on page
The math variables listed in
predefined math expressions in B2980. The predefined math variables are not
cleared by the power off and on operations. At power-on or resetting (by the
*RST command or the device clear), 0 is set for all predefined math variables.
Table 5-3 are reserved for reading the measurement
Table
Table 5-5 have already been defined for the
Keysight B2980B User's Guide, Edition 1
5-4.
178.