Specifications

102 Chapter 4
Preparation for Accurate Measurement
Fixture Compensation
Example program using macro (E4991A VBA)
The program shown in Example 4-6 is saved under the filename com_meas.bas on the
programs disk. The details of this program are explained as follows.
Lines 110 - 120 Substitutes a variable for the type of text fixture and the obtained
fixture compensation data point.
Lines 140 - 150 Sets the type of test fixture and the obtained fixture compensation data
point.
Lines 170 - 200 When a custom test fixture is selected (defines variable of Fixt_type to
USER), defines the electrical length of the test fixture.
Line 220 Asks whether to define the standard values for the fixture
compensation kit with the values prepared by the user.
Line 230 When the standard value is defined with the values prepared by the
user, the program branches to define each standard value of the fixture
compensation kit.
Line 250 Without using the list-setting function of the fixture compensation kit,
selects a setting that defines each standard value at a common unique
value over all frequencies.
Lines 270 - 350 Defines the standard values of Open (G-C) and Short (R-L). The
definition of each standard value is performed in the procedure
(Inp_data).
Lines 390 - 430 Measures the fixture compensation data for the Open/Short standard.
This measurement is performed in the function program (Fixt_comp).
When measurement is aborted during fixture compensation, the
function program returns the value of -1 and stops execution of the
fixture compensation.
Lines 450 - 470 Calculates the fixture compensation coefficient and turns on the
fixture compensation function. After that, displays completion of
fixture compensation.
Lines 490 - 530 Reads the two arrays of the fixture compensation coefficients in ASCII
transfer format.
Lines 550 - 560 Reads the number of measurement points.
Lines 580 - 690 Saves the two fixture compensation coefficient arrays to a floppy disk.
After that, displays completion of transferring the fixture
compensation coefficient arrays.
Line 710 Stops the execution of the macro.
Line 790 Prompts connection of the standard for fixture compensation
measurement specified by the variable of the Standard.
Lines 840 - 890 Measures the fixture compensation data by the CompenMeasure
method after the standard is connected. The CompenMeasure method
returns the value of 1 when measurement is completed without
problem and the value of 0 when measurement is aborted during
fixture compensation.
Lines 900 - 950 Displays a message when measurement is aborted, and the function
program returns the value of -1. When measurement is completed