Signal calculator

Use the Signal calculator computed channel to create logical, arithmetic or trigonometric expressions combining other channels, functions and constants.

ClosedGeneric parameters

  • Name: Enter a name for the channel. The name must be unique and contain valid characters (invalid characters are single and double quotes, '\', '@', '#', '&', '<' and '>'). Invalid channel names are 'true' and 'false' (case sensitive).
  • Collect: Select the Collect checkbox to write the channel data to the SIE data file during a test run.
  • Description: Enter an optional detailed description of the computed channel.
  • Measurand: Enter the quantity being measured or the type of measurement associated with the computed channel.
  • Units: Enter the physical units of measurement for the computed channel.
  • Range min and Range max: Enter the expected extreme values of the computed channel output.
  • Channels: All input channels to a single Signal calculator channel must have the same sample rate, which also determines the computed channel sample rate.
  • Operators and functions: See More functions information below.
  • Constants: Constants cannot start with a decimal point (e.g., the term “.55” is invalid, but the terms “0.55”, “-0.55” and even “+0.55” are valid).
  • Expression: Double-click or drag and drop a channel or operator to add it to the Expression panel. Alternatively, build the expression using keyboard entry. All operators and referenced input channels are case sensitive.

NOTE
When using drag and drop to select channels and functions, the item is dropped at the current position of the cursor.

More functions information

Category Operator Syntax Return
Logical > a > b TRUE if a is greater than b; else FALSE
>= a >= b TRUE if a is greater than or equal to b; else FALSE
< a < b TRUE if a is less than b; else FALSE
<= a <= b TRUE if a is less than or equal to b; else FALSE
== a == b TRUE if a is equal to b; else FALSE
!= a != b TRUE if a is not equal to b; else FALSE
! !a TRUE if a is FALSE; else FALSE
&& a && b TRUE if a and b are TRUE; else FALSE
|| a || b TRUE if either a or b are TRUE; else FALSE
Arithmetic ^ a ^ b a raised to the power of b
* a * b The product of a and b
/ a / b The quotient of a and b
% a % b The modulus of a and b
+ a + b The sum of a and b
- a - b The difference of a and b
fabs fabs(a) The absolute value of a
sqrt sqrt(a) The square root of a
log log(a) The natural logarithm of a
log10 log10(a) The base-10 logarithm of a
exp exp(a) The exponential function of a
sgn sgn(a) -1 for a < 0, 1 for a > 0, 0 for a = 0
float float(a) Logical channel a converted to floating point
floor floor (a) The largest integer less than or equal to a
ceil ceil(a) The smallest integer greater than or equal to a
Trigonometric
(all angles in radians)
sin sin(a) The sine of a
cos cos(a) The cosine of a
tan tan(a) The tangent of a
asin asin(a) The arcsine of a in the range [-PI/2, PI/2]
acos acos(a) The arccosine of a in the range [0, PI]
atan atan (a) The arctangent of a in the range [-PI/2, PI/2]
sinh sinh(a) The hyperbolic sine of a
cosh cosh(a) The hyperbolic cosine of a
tanh tanh(a) The hyperbolic tangent of a
Pi pi() Function used to return Pi {3.141592653589793}