Trends

[Guest Gary Dakin]

I'm experimenting with trends. I'm trying to create a trend of a temperature (AI1) assigned to MI1.

Just for learning purposes when I create the trend I give it a History Samples Value of 100. How does the software know where to store the 100 values.

[Joe Tauser]

The PLC allocates memory based on what the user has defined in the application, and Trends are their own animal (not to be confused with user accessible memory such as MBs and MIs). You can't look at the actual Trend data, it's only accessible by the Trend object.

In Visilogic, go to Build->Projected Memory Map to see what I'm talking about. You can also save Trend data to an SD card, but to view it you have to load it back.

Joe T.