Moving Average
The Moving Average (MOV) calculates the average of a numeric tag over a moving time window, e.g. over the last hour in each case. It smooths out short fluctuations and is required, for example, in the water industry, where limit values are often specified as a moving hourly average.
Function parameters
| Source | Numeric tag whose average is calculated. |
| Time window | Period over which values are averaged (e.g. 1 hour). |
How it works
Unlike an hourly average, which always starts anew on the hour, the time window moves continuously. At 10:25, the average is therefore calculated over the period from 9:25 to 10:25, at 10:26 over 9:26 to 10:26, and so on.
The average is time-weighted: Each value is included with the duration for which it was valid. A value that was present for 50 minutes therefore counts more than a value that was only present for 10 minutes, regardless of how often the source sent its value.
Notes
- The larger the time window, the smoother but also the slower the curve.
- Immediately after creation, a complete time window is not yet available. The average then refers to the period available so far.
- If the data of an offline period of the source is transmitted later, the average is recalculated for this period.