The limit test is a function of automatic pass/fail judgment for the trace of the measurement result. The judgment is based on the comparison of the trace to the limit line set by the user.
The limit line can consist of one or several segments (See figure below). Each segment checks the measured value for failure, whether it is an upper or lower limit. The limit line segment is defined by specifying the coordinates of the beginning (X0, Y0) and the end (X1, Y1) of the segment, and the type of the limit. The MAX or MIN limit types check if the trace falls outside of the upper or lower limit respectively.
Limit line
The limit line is set by the user in the limit table. Each row in the table describes one segment of the line. Limit table editing is described below. The table can be saved into a *.LIM file.
The display of the limit lines on the screen can be turned ON/OFF independently of the status of the limit test function.
The result of the limit test is indicated:
•If the measurement result passed the limit test, Pass sign will be displayed in green in the center of the window.
•If the measurement result failed, the result will be indicated in the following ways (See figure below):
1.Fail sign will be displayed in red in the center of the window.
2.The points of the trace, which failed the test will be highlighted in red.
Test fail indication
Limit Test Enabling/Disabling
To enable/disable limit test function use the Analysis > Limit Test > Limit test softkeys.
|
Limit Line Editing
To access the limit line editing mode, use the Analysis > Limit Test > Edit Limit Line softkeys. The Edit Limit Line dialog will appear on the screen.
|
Navigating within the table to enter the values of the following parameters of a limit test segment:
Begin Stimulus |
Stimulus value in the beginning point of the segment. |
End Stimulus |
Stimulus value in the ending point of the segment. |
Begin Response |
Response value in the beginning point of the segment. |
End Response |
Response value in the ending point of the segment. |
Type |
Select the segment type among the following: •MAX — upper limit. •MIN — lower limit. •OFF — segment not used for the limit test. |
Select the required parameter in the table and double click on the corresponding cell. Enter the required value Begin Stimulus, End Stimulus, Begin Response, End Response, and Type using the on-screen keypad. To add a new row in the table click Add softkey. The new row will appear below the highlighted one. To delete a row from the table, click Delete softkey. The highlighted row will be deleted. To clear the entire table, use Clear Limit Table softkey. To save the table into *.LIM file, use Save Limit Table softkey. To open the table from a *.LIM file, use Restore Limit Table softkey.
|
Limit test display management
To enable/disable display of a limit line, use the Analysis > Limit Test > Limit Line field. To enable/disable display of fail sign in the center of the diagram, use Fail Sign field.
|
Limit Line Offset
The limit line offset function allows the user to shift the segments of the limit line by the specified value along X and Y axes simultaneously.
To define the limit line offset along X-axis, use the following softkeys Analysis > Limit Test. Click on the Stimulus Offset field and enter the value using the on-screen keypad. To define the limit line offset along Y-axis, click on the Response Offset field and enter the value using the on-screen keypad.
|
