Agilent Technologies 4294A Programming Manual page 68

Preparing For Accurate Measurement
Fixture Compensation
Example 4-4 shows a sample program that takes in data for use in fixture compensation.
This sample program is given the file name com_inpu.bas and is stored on the sample
program disk.
This program reads open data, short data and load data from the files (COM_DATA and
STD_VAL) retained by the program shown in Example 4-3 and sets them.
Lines 50 to 140
Lines 150 to 180
Lines 220 to 250
Lines 290 to 310
Lines 330 to 350
Lines 390 to 440
Line 480
Line 490
Lines 510 to 580
Example 4-4 Data entry for fixture compensation
10
20
30
40
50
60
70
80
90
100
110
120
130
140
68
These lines distinguish between the external controller and Instrument
BASIC and set the GPIB address and the select code. In the case of
Instrument BASIC, flash memory is used as the storage unit.
These lines substitute the selection of data measurement points, the
number of compensation data measurement points (100 for fixed
measurement points), the name of the file for reading compensation
data, and the name of the file for reading standard value to the
variables Cal_point$, Point, File$ and Std_file$, respectively.
These lines reset the Agilent 4294A and then assign the data
measurement points to Cal_point$.
These lines read open data, short data and load data from the file
named File$ in the sequence shown in Example 4-3 to store them in
the arrays Com_o(*), Com_s(*), and Com_l(*), respectively.
These lines read open/short/load standard values from the file named
Std_file$ in sequence as written in Example 4-3 and store them in the
variables Open_g, Open_c, Short_r, Short_l, Load_r, and Load_l
respectively.
These lines set the standard values. The open standard capacitance
needs to be in femtofarad, so these lines make the necessary
conversion.
This line selects the IEEE 64-bit floating-point format for the data
transfer format.
This line calculates data size from the program variable Point and
creates a header to be used at the time of data transfer.
These lines enter data for open/short/load compensation. When the
data are entered, the open/short/load compensation of the fixture
compensation functions is turned on.
DIM Header$[9],Cal_point$[9],File$[20],Std_file$[20]
DIM Com_o(1:100,1:2),Com_s(1:100,1:2),Com_l(1:100,1:2)
REAL Open_g,Open_c,Short_r,Short_l,Load_r,Load_l
INTEGER Scode,Point
IF SYSTEM$("SYSTEM ID")="HP4294A" THEN
ASSIGN @Hp4294a TO 800
ASSIGN @Binary TO 800;FORMAT OFF
MASS STORAGE IS ":INTERNAL1,5"
Scode=8
ELSE
ASSIGN @Hp4294a TO 717
ASSIGN @Binary TO 717;FORMAT OFF
Scode=7
END IF
Chapter 4