Understanding Statistical Process Control Blocks

The block...

Function:

Histogram (HS)

Displays an input value's frequency of occurrence.

Pareto (PA)

Accepts, calculates, and sorts the frequency of up to eight input values. You can display these values in an operator display with filled rectangles to create a bar chart.

Statistical Control (SC)

Adjusts a process variable based on calculations of the average offset and the rate of deviation from a target value, XBARBAR. This block is activated if an alarm is generated by a Statistical Data block.

Statistical Data (SD)

Observes data from operator input or other blocks and performs statistical calculations. This block allows for alarming based on standard SPC techniques.