You are here: NI Home > Support > Product Reference > Manuals > LabVIEW 8.6 Datalogging and Supervisory Control Module Help

Owning Palette: Statistical Process Control VIs

Installed With: Statistical Process Control Toolkit. The objects available on this palette vary according to the packages you have installed.

The Control Charts VIs include variables charts, attributes charts, and rule-checking VIs. The Control Chart VIs compute control limits for control charts, create control chart graphs, and apply rules to control chart data that detect out-of-control conditions.

Palette Object	Description
c Chart	Computes points and limits for a c chart, a control chart for number of non-conformities or defects. Optionally, you can choose a range of indices for samples to use and indices of samples to ignore in the control calculation. The actual number of samples the VI uses to calculate the control limits is also output. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.
Check Control Limits	Given a set of control chart points, and the upper and lower control limits from the control chart VIs, this VI checks for points that exceed the control limits. If such points exist, the VI lists the index of each point that exceeds the limits, in the order of how much each point exceeds the control limits.
mX-bar & mR Chart	Computes points and limits for mX-bar and moving Range charts. These are control charts for charting moving average and moving range. This VI computes moving average and range over n observations. By default, n is 2. Optionally, you can choose a range of indices for individuals to use and indices of individuals to ignore in the control calculation. The actual number of individuals the VI uses to calculate the control limits is also output. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.
np Chart	Computes points and limits for an np chart, a control chart for number non-conforming. Optionally, you can choose a range of indices of samples to use and indices of samples to ignore in the control calculation. The actual number of samples the VI uses to calculate the control limits is also output. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.
p Chart	Computes points and limits for a p chart, a control chart for fraction non-conforming. Number of units inspected can be constant for all or vary for each element of r. Calculates both variable and constant chart limits. Optionally, you can choose a range of indices for samples to use and indices of samples to ignore in the control calculation. The actual number of samples the VI uses to calculate the control limits is also output. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.
Process Shift Detector	Uses run rules to detect a process shift in a control chart with respect to the center line. Returns whether or not a process shift was detected, and if so, the index of the first point of shift and the pattern detected are output. This VI can be used to determine when to recalculate control limits.
Rule Checker(AT&T_WE)	Applies AT&T_Western Electric run rules to the input points array. Given a set of control chart points, and the center line and std error from the control chart VIs, this VI checks whether points are out of control (or non-randomly distributed) according to the rules enabled. The front panel of this VI lists which rules you can enable. The VI outputs the rules that are violated along with the first point and length of the sequence of points violating the rule, and a list of all points violating any of the enabled rules.
Rule Checker(Nelson)	Applies Nelson tests to the input points array. Given a set of control chart points, and the center line and std error from the control chart VIs, this VI will check whether points are out of control (or non-randomly distributed) according to the enabled Nelson tests.
Sequence Checker	Searches Boolean input array point exceeds bound for # violations per run set to TRUE within run length. Values in the point exceeds bound array are set to TRUE if they violate some rule limit. Returns arrays with the index of each violation point and run length associated with that point. You use this VI as a generic building block in the rule checker VIs.
Single Point X-bar & R_S	Computes single points for both X-bar and Range or X-bar and s control charts. Computing single points is useful for plotting control charts one point at a time while you are collecting samples. You must continue to use the X-bar & R or X-bar & s Chart VIs to calculate the control limits for the chart.
Single Point x_mX-bar & mR	Computes single points for the x and moving range or moving average and moving range control charts. Computing single points is useful for plotting control charts one point at a time while you are collecting samples. You must still use the x & mR Chart or mX-bar & mR Chart VIs to calculate the control limits for the chart. This VI is reentrant so that you can use multiple copies. Each time it is called, this VI saves a copy of the previous n-1 individuals to use in calculating the next moving Average and Range.
u Chart	Computes points and limits for a u chart, a control chart for fraction of non-conformities or defects. Number of units inspected n can be constant for all c or vary for each element in c. Calculates both variable and constant chart limits. Optionally, you can choose a range of indices for samples to use and indices of samples to ignore in the control calculation. The actual number of samples the VI uses to calculate the control limits is also output. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.
x-bar & R Chart	Computes points and limits for x-bar and range control charts. These are control charts for charting mean and range. Optionally, you can choose a range of indices for samples to use and indices of samples to ignore in the control limit calculation. The VI outputs the actual number of samples it uses to calculate the control limits.
x-bar & S Chart	Computes points and limits for X-bar and s control charts. These are control charts for showing mean and sample standard deviation. Optionally, you can choose a range of indices for samples to use and indices of samples to ignore in the control limit calculation. The VI outputs the actual number of samples used to calculate the control limits. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.
x & mR Chart	Computes points and limits for individuals x and moving Range charts. These are control charts for charting mean and moving range. This VI computes for a moving range from n consecutive observations. By default, n is two. Optionally, you can choose a range of indices for individuals to use and indices of individuals to ignore in the control calculation. The actual number of individuals the VI uses to calculate the control limits is also output. By default, control limits are calculated from the input samples. You can also calculate control limits from standard values by wiring the chart limit src input.

Subpalette	Description
Control Charts Drawing VIs	Use the Control Charts Drawing VIs for graphing control charts and raw process data.

My Profile | Privacy | Legal | Contact NI   © 2009 National Instruments Corporation. All rights reserved.   |