Agilent Technologies 4294A, Руководство по программированию

Страница: 68 / 518

68 Chapter 4
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 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.
Lines 150 to 180 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$, respectively.
Lines 220 to 250 These lines reset the Agilent 4294A and then assign the data
measurement points to Cal_point$.
Lines 290 to 310 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.
Lines 330 to 350 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.
Lines 390 to 440 These lines set the standard values. The open standard capacitance
needs to be in femtofarad, so these lines make the necessary
conversion.
Line 480 This line selects the IEEE 64-bit floating-point format for the data
transfer format.
Line 490 This line calculates data size from the program variable Point and
creates a header to be used at the time of data transfer.
Lines 510 to 580 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.
Example 4-4 Data entry for fixture compensation
10 DIM Header$[9],Cal_point$[9],File$[20],Std_file$[20]
20 DIM Com_o(1:100,1:2),Com_s(1:100,1:2),Com_l(1:100,1:2)
30 REAL Open_g,Open_c,Short_r,Short_l,Load_r,Load_l
40 INTEGER Scode,Point
50 IF SYSTEM$("SYSTEM ID")="HP4294A" THEN
60 ASSIGN @Hp4294a TO 800
70 ASSIGN @Binary TO 800;FORMAT OFF
80 MASS STORAGE IS ":INTERNAL1,5"
90 Scode=8
100 ELSE
110 ASSIGN @Hp4294a TO 717
120 ASSIGN @Binary TO 717;FORMAT OFF
130 Scode=7
140 END IF