TORATE
Parameters
| Order | Name | Type | Desc |
|---|---|---|---|
| 1 | a | point list | A list of points that have history |
| 2 | b | Const | Optional Time-scale in seconds for the rate (defaults to 1 second) |
Returns
Returns a point list - the historical values within the point are converted from a total value (usually a feed from a totaliser or counter) into a rate-of-change.
Description
This function is used convert points that have history (ie. from a call to GETHISTORY) from a counter to a rate of change.
This function deals with some specific issues in the conversion process. For example, drops down to zero are ignored. This allows you to create a rate-of-change based on hourly or daily totals.
It also deals with situations where your data sampling rate and the measurement rate are very different. If you are sampling your data at 1-sample-per-second, but the counter is only ticking up every 10 seconds, this function will interpolate those changes over the 10 seconds.
The optional time-scale parameter controls the time-basis for the final measurement. Without the parameter, the calculated rate will be per second.
With a time-scale of 60, your results will be per minute, and at 1440 you'll have an hourly rate.
NOTE: This function can produce rough signals if the counter is slow. We suggest using the SMOOTH function to make your results cleaner.