Specification Limit Alarm 
Specification limits fall on either side of the center line. The specification limit alarm rule checks for points that are beyond a specification limit.
For alarm rule 9, the limit and length values are used for both the upper and lower charts and for the upper and lower specification limits. The data points on the chart are compared to the specification limits. For alarm rule 9, an alarm is triggered when there are <Limit> number of data points in the <Length> that occur on either side of the specification limits. You can also use alarms 44, 45, 46, or 47.
Features
Following are the alarm properties defined for Specification Limit Alarm:
Alarm Name | Property Name | Parameter | Data Type | Description |
|---|---|---|---|---|
Allow Upper Chart Specification Limit Alarm | UpperWESpecificationLimitAlarmEnabled | Boolean | Enables specification limit alarms for upper charts | |
Allow Lower Chart Specification Limit Alarm | LowerWESpecificationLimitAlarmEnabled | Boolean | Enables specification limit alarms for lower charts | |
Alarm 9 | Alarm Limit for Specification Limit | WESpecificationLimitAlarmLimit | Integer | Sets the limit and length values to check for alarms that are beyond specification limits |
Alarm Length for Specification Limit | WESpecificationLimitAlarmLength | Integer | ||
Alarm 44 | Alarm Limit for Upper Chart Upper Spec. Limit | WEUpperChartUSLAlarmLimit | Integer | Defines the limit and length values to check for points outside upper specification limits of upper chart |
Alarm Length for Upper Chart Upper Spec. Limit | WEUpperChartUSLAlarmLength | Integer | ||
Alarm 45 | Alarm Limit for Upper Chart Lower Spec. Limit | WEUpperChartLSLAlarmLimit | Integer | Defines the limit and length values to check for points outside lower specification limits of upper chart |
Alarm Length for Upper Chart Lower Spec. Limit | WEUpperChartLSLAlarmLength | Integer | ||
Alarm 46 | Alarm Limit for Lower Chart Upper Spec. Limit | WELowerChartUSLAlarmLimit | Integer | Defines the limit and length values to check for points outside upper specification limits of lower chart |
Alarm Length for Lower Chart Upper Spec. Limit | WELowerChartUSLAlarmLength | Integer | ||
Alarm 47 | Alarm Limit for Lower Chart Lower Spec. Limit | WELowerChartLSLAlarmLimit | Integer | Defines the limit and length values to check for points outside lower specification limits of lower chart |
Alarm Length for Lower Chart Lower Spec. Limit | WELowerChartLSLAlarmLength | Integer |
Example
If you define alarm rule 44 with limit and length as 1 each, the rule is violated if only 1 point in a string of 1 adjacent point is beyond the upper specification limit on the upper chart. In the below illustration, one violation is for a point above the upper specification limit, while the other is for a point below the lower specification limit.
Graphical representation of Specification Limit Alarm
