Setting Signal Properties

To see the properties of a Signal, right-click on the name of the desired Signal inside the TestCase window, and select Properties. You will see as many as three tabs, which are displayed when appropriate. These properties apply only to the Signal in the current TestCase. For classifications and more properties, see Signal Dictionary.

You can review and modify the following properties:

hmtoggle_plus1Y-Axis/Display Settings Tab

There are two versions of the Display Settings tab depending on the Signal Classification:

SignalProperties-Display

•Units: This setting enables you to select the units used to display the Signal.

•Y-Axis Scale

oMinimum: This is the minimum value for the Signal.  It is stored in the Signal Dictionary and cannot be modified here. When checking is enabled, a failure is indicated if the actual Signal value goes below this minimum.

oMaximum: This is the maximum value for the Signal.  It is stored in the Signal Dictionary and cannot be modified here. When checking is enabled, a failure is indicated if the actual Signal value goes above this maximum.

•Y-Axis Scale buttons: Choose one option:

oDefault: This option sets the Y-Axis minimum and maximum to the values in the Signal Dictionary.

oManual: Select this option to enter the Y-Axis minimum and maximum in the unlabeled text boxes.

oAuto: When this option is selected, the Y-Axis minimum and maximum are calculated based on the transition values in the displayed range.

oSignal Display Min: This unlabeled text box allows you to specify a lower bound for the visible portion of the graph when plotting this Signal.  The Y-Axis Auto Scale and Default Scale toolbar buttons adjust this value.

oSignal Display Max: This unlabeled setting allows you to specify an upper bound for the visible portion of the graph when plotting this Signal.  The Y-Axis Auto Scale and Default Scale toolbar buttons adjust this value.

You can drag a Signal's plot line to any value in the Y-Axis Scale. You can use the transition properties to set any value. See Editing Test Patterns. You may wish to use a value outside the signal min/max range for testing purposes.  Suppose you have a temperature stimulus signal with a max of 100 degrees. You may wish to test your system with a commanded value of 110 degrees. If a Scale setting is outside the min/max boundaries, it is displayed in red.

•Apply: Click this button to apply a changed scale to the Signal Y-axis without closing the dialog. You can view the display and change it again if desired.

 

This tab controls how message Signals are displayed in the Transition List and in the pop-ups (also known as tool tips) that are displayed when you mouse-over a transition.

SignalProperties-Messages

The following text encodings are supported:

•UTF-8 (includes ASCII)

•UTF-16 (Little-Endian Unicode)

•UTF-16BE (Big-Endian Unicode)

•UTF-32 (32-bit Unicode)

•UTF-7 (7-bit encoding)

For an example, see the String Sample Project.
hmtoggle_plus1Pass Fail Criteria Tab

The Pass/Fail Criteria tab is displayed for numeric response Signals.  For more detailed information about the mechanism for determining Pass/Fail, refer to Pass/Fail Judgment Overview. Default Pass/Fail judgment settings can be defined in the Signal properties. The tolerance settings can be overridden for each DataBlock.

SignalProperties-PassFail

Pass/Fail Algorithm

For Numeric Output Signals there are two Pass/Fail algorithms that may be used during Pass/Fail judgment. One is designed primarily for Continuous Signals and the other for Discrete Signals. The algorithm used by default is selected based on the classification of the Signal in Signal Dictionary (Continuous or Discrete). This default selection can be overridden here. For more information, see Pass/Fail Algorithms.

This selection also controls how the Accept Results command works.

Require Periodic Transitions

This is used to test periodic Signals. When this box is checked, each transition must be no more than the specified Period Maximum after the previous transition or the test fails. See Periodic Signals.

Value Tolerance

You can set upper and lower tolerances on numeric response Signals. The default, the tolerances are specified in the Signal Dictionary, but they can be overridden here. If a tolerance is specified here, the values apply to the current TestCase only.

For the test to pass (assuming other criteria are met), the Actual Value measured must be less than or equal to the Expected Value plus the Upper Tolerance and greater than or equal to the Expected Value minus the Lower Tolerance.  Tolerances can be defined in either Engineering Units or Counts.

•Basic (Fixed)

Basic tolerances are numeric values that are applied to all transitions on the Signal. The tolerances do not change during the test.

•Custom (Calculated)

Custom Tolerances are defined by a C# code snippet. In the code, assign the Positive Tolerance to TolValUpper and the Negative Tolerance to TolValLower.  Predefined Constants and the variables time and value can be used in the calculation. time is the TestCase time and value is the expected value. The value of the Constant may change based on the tags associated with it.

The tolerances are recalculated for each transition on the Signal; thus they may change during the test.

Click the Compile button to check your code for syntax errors, then click OK.

Tolerance-snippet

Note that default Time Tolerances are set at the TestCase level.  They can be overridden in the DataBlock.
hmtoggle_plus1Other Properties Tab

SignalProperties-Other

The Properties pane summarizes some of the information specified in the Signal Dictionary.  It cannot be modified here.

The Do not Auto Scale in Reports option controls how the Signal is displayed in reports. See Y-Axis Auto Scale.

Show Cursors: Select this box to display these cursors: Start Time, End Time, Time Range, Min, Max, Value Range. You can move the Start Time and End Time cursors by dragging with the mouse.

Cursors

 

Related Topics:

Using the Signal Dictionary

Signal Classification

Pass/Fail Judgment Overview

Viewing Signals

Editing Ports (setting port properties in MxTransIt)