Data trending provides two main functions: (1) Track minimum, maximum, and average, and (2) graph the trend over some recent period.

The min-max-average trending is meaningful when trending is being logged either to a data file or via HTTP Get to a remote server. At the end of each tracking period, the data is logged, and then trend values are reset. If no logging is being done, the min-max-average values will have little meaning since they are essentially "average forever" values. However, the graph is still useful without logging because it is always a sliding window of actual data samples.

Trending is set up under the System->Action Rules->Trending tab. You simply select which data point you with to track and identify it by register number. Then allocate destination registers for the trend results. You can use the auto-allocate button for this.

Trend data may be viewed under the System->Data->Trend Data tab. The values that will be logged next if logging is enabled will appear here. You have the option of resetting the values. The illustration below shows that the trend has just been reset, in which case minimum, maximum, and average are the same value.