Tag Formula Variables
When you Add Tags, you have the option of adding a formula to process the generated data.
You can use the following variables:
- value: The current tag value.
- timestamp: The time the tag value was generated represented in UNIX time in milliseconds.
You can use the following functions.
Note: For additional functions on tag values such as rounding and data conversions, you can use Analytics or the Flows Manager.
Function | Description | Use |
---|---|---|
sin (sine) | The ratio of the side opposite a given angle (in a right-angled triangle) to the hypotenuse. | Analysis and control of periodic processes. |
cos (cosine) | The ratio of the side adjacent to an acute angle (in a right-angled triangle) to the hypotenuse. | Analysis and control of periodic processes. |
sqrt (square root) | The square root of a number is the factor that you can multiply by itself to get that number. | Identify deviations from expected values or detect abnormal conditions. |
tan (tangent) | The ratio of the sine of an angle to the cosine of that angle. | Used in calibration formulas to correct or compensate for non-linearities. |
power | A function with a single term that is the product of a real number, a coefficient, and a variable raised to a fixed real number. power(x) is equivalent to 10^x. | Perform exponentiation when converting values between different units or applying non-linear scaling. |
log (logarithm) | The inverse function to exponentiation. log(x) is equivalent to the natural logarithm of x (a logarithm with base e). | Perform logarithmic scaling or conversion when there is a non-linear relationship between the register value and the desired output. |
exp (exponential) | Calculates the exponential growth or decay of a given set of data. exp(x) is equivalent to the exponential function e^x. | Perform exponential scaling or conversion when there is a non-linear relationship between the register value and the desired output. |