Agilent Technologies 4288A, Programming Manual, Page: 40 / 289

38 Chapter 4
Preparation for Accurate Measurement (Executing Compensation)
Executing OPEN/SHORT/LOAD Compensation
Sample program
Example 4-1 shows a sample program to execute the OPEN/SHORT/LOAD
compensation. Example 4-2 shows a sample program to read out and recall compensation
data saved in a file. These programs are stored on the sample program disk under the
filenames “compen.bas” and “comp_dat.bas.”
Example 4-1 executes the OPEN/SHORT/LOAD compensation and then saves the
compensation state (each compensation data item, LOAD compensation standard
definition value, cable length, and frequency shift) into a file.
The program details of Example 4-1 are described below.
Line 50 Sets the GPIB address.
Line 70 Assigns the filename for saving the compensation state (Cmp_data) to
the File_name$ variable.
Line 90 Resets the instrument.
Lines 110 to 160 Uses the FNCompen sub-program to execute the
OPEN/SHORT/LOAD compensation.
Line 180 Uses the Save_comp_data sub-program to save the compensation state
to a file whose name is File_name$.
The FNCompen sub-program of Lines 210 to 1150 used to execute the compensation is
described below.
Lines 290 to 300 Reads out the setup of the current measurement frequency and sets it
to the Curr_freq variable.
Lines 310 to 320 Sets the measurement frequencies (1 kHz and 1 MHz) in the Freq
array.
Line 330 Assigns the LOAD compensation standard definition parameter
(Cp-D) to the Load_para$ variable.
Lines 340 to 350 Makes the setup generate SRQ when measurement of compensation
data is finished.
Line 380 If the value of Standard$ is “Open,” assigns the parameter (STAN1)
used at the execution of the compensation data measurement
command to the Std$ variable.
Line 400 If the value of Standard$ is “Short,” assigns the parameter (STAN2)
used at the execution of the compensation data measurement
command to the Std$ variable.
Lines 420 to 510 If the value of Standard$ is “Load,” assigns the parameter (STAN3)
used at the execution of the compensation data measurement
command to the Std$ variable. Then, for both 1 kHz and 1 MHz,
obtains and sets up the LOAD compensation standard definition value
(Cp, D) using the Inp_data sub-program by user entry.
Lines 540 to 550 Prompts the user to make the connection for the compensation
specified with Standard$. After the connection, waits for the user to
enter the y key and Enter key.
Lines 570 to 1060 Repeats the following twice (for 1 kHz and 1 MHz).
1. Lines 580 to 590: Displays the measurement frequency and sets