Limits Tab

The Limits tab contains the following options:

• Comparison Type —The type of comparison the step type performs to determine the step status . The following table lists the available comparison types. Comparisons use 14 digits of precision.

  Type	Description
  EQ (==)	Numeric Measurement = Low Limit
  EQT (==+/-)	Numeric Measurement >= Computed Low Limit and <= Computed High Limit, as shown in the table following the Threshold Type option below.
  NE (!=)	Numeric Measurement != Low Limit
  GT (>)	Numeric Measurement > Low Limit
  LT (<)	Numeric Measurement < Low Limit
  GE (>=)	Numeric Measurement >= Low Limit
  LE (<=)	Numeric Measurement <= Low Limit
  GTLT (><)	Numeric Measurement > Low Limit and < High Limit
  GELE (>=<=)	Numeric Measurement >= Low Limit and <= High Limit
  GELT (>=<)	Numeric Measurement >= Low Limit and < High Limit
  GTLE (><=)	Numeric Measurement > Low Limit and <= High Limit
  LTGT (<>)	Numeric Measurement < Low Limit or > High Limit
  LEGE (<=>=)	Numeric Measurement <= Low Limit or >= High Limit
  LEGT (<=>)	Numeric Measurement <= Low Limit or > High Limit
  LTGE (<>=)	Numeric Measurement < Low Limit or >= High Limit
  No Comparison	TestStand makes no Pass/Fail determination, and sets the status to Passed automatically.

• Threshold Type —The type of threshold the step type uses to compute the low and high limit values to be used with the EQT (== +/-) comparison type to determine the step status. This control is available only when you use the EQT (== +/-) comparison type. The following table lists the available threshold types and how the step type computes the Low Limit and High Limit for each threshold type.

  Threshold Type	Computed Low Limit	Computed High Limit
  Percentage (% of Nominal Value)	Nominal Value - (Nominal Value * Lower Threshold / 100)	Nominal Value + (Nominal Value * Upper Threshold / 100)
  Parts Per Million (PPM of Nominal Value)	Nominal Value - (Nominal Value * Lower Threshold / 1000000)	Nominal Value + (Nominal Value * Upper Threshold / 1000000)
  Delta Value (Variation from Nominal Value)	Nominal Value - Lower Threshold	Nominal Value + Upper Threshold

• Nominal Value —The base limit value, when you use the EQT (== +/-) comparison type. This control is available only when you use the EQT (== +/-) comparison type.
• Low Limit —The lower limit when you use comparisons that have two limits. Also specifies the limit when you use comparisons that have only one limit.
• High Limit —The higher limit when you use comparisons that have two limits. This control is not available when you use comparisons that have only one limit.
• Measurement Must Be —The one or two limit values the step uses to perform the limit comparison.
• Units —A label that describes the measurement units for the limits and the value for which the step checks limits. The units you specify appear in both the report and the result database.

  Use the drop-down ring controls adjacent to the Units control to select standard units and prefixes. Select the Short Name option in each ring control to toggle between the long and short names for a unit or prefix.

  Note The unit and unit prefix are for display and documentation purposes and do not scale the measured value or affect the limit comparison.

You can choose to display the limit values in real, integer, unsigned integer, hexadecimal, octal, or binary formats. Click Numeric Format to launch the Numeric Format dialog box, in which you can further customize the format with which to display the limit values. Changes to the numeric format do not affect the limit values or the comparison operation the step performs.

See Also

Numeric Format dialog box