SPC can track several different types of occurrences to warn you if a process is slightly off, even if production has not exceeded its control limits on a regular basis. As a result, you can anticipate and handle potential problems before they occur.
Use the Alarm tab in the Variable Quality Characteristics Properties box to specify the:
Type of alarm that will be
triggered.
Setpoint ID.
Control test criteria that
will initiate alarms or change Setpoints.
Alarms and Setpoints
When one of the control tests meets your criteria for issuing a warning, it will generate the type of warning you configure, including:
An alarm to alert
operators.
If alarms are generated for more than one control test, they will stack up and be deleted according to specifications you enter in the CIMPLICITY Alarm Configuration.
A Setpoint that will change
to the number (1-8) of the XBar test that is in an alarm state.
Setpoints provide you with a way to automate corrective action. You can write scripts that trigger the appropriate action whenever the criteria have been met for one of the control tests. The value of the Setpoint reflects the last test for which an alarm was triggered.
To specify an alarm and Setpoint:
Select the Alarm tab.
Do one of the following:
Select the $SPC_ALARM
system Alarm ID, or
Create your own alarm in
the Alarm ID field.
Tip: Use the SPC_ALARM type when creating your own alarm. Do one of the following:
Click
to browse for an existing
Point in the Select a Point dialog box, or
Click 
to designate a New Point.
The alarm message for SPC alarms consists of the following strings:
Document Name.
Product Name.
Quality/Defect
Characteristic Name.
A description of the
control check that triggered the alarm.
The value of the sample
that triggered the alarm.
In the Setpoint ID field, indicate a Point to be set when an SPC alarm occurs as follows:
Click to browse for an existing Point
in the Select a Point dialog box, or
Click to designate a New Point.
Check the Alarm enabled box to activate alarming for the variable; clear to disable option.
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Step 3. Add and configure variable quality characteristics. |
