Two Ways to Use Control Quality Analysis

This section describes the source data for the line chart that shows the Variable Value Changing Chart. As shown below, you can select one of two sources for the data of the line chart. In the graph we displayed earlier, we used choice (1). Each method has its own advantages and disadvantages, so select the method that suits your needs.

(1) Real-time Sampling

This method uses variable values called at a user-defined interval during program execution as the source data.

Advantages: Also available on the MINICUBE series, which does not have a trace function.

Enables sampling over a relatively long time period.

Disadvantages: Because the minimum sampling interval is 100 ms, it is not able to track changes at intervals shorter than this.

(2) Trace Data Analysis

This method uses histories of access variables in trace data.

Advantages: Able to graph all changes to variables. (Except when CPU is not used, such as DMA)

Disadvantages: Not available on the MINICUBE series, which does not have a trace function.

It is not able to sample for very long periods of time, because it depends on the size of the trace memory and the frequency of variable access by the CPU.