58542 VXIbus Universal Power Meter
A-32 Publication 21555, Rev. E, September 2002
A.7.5 Cal Factor Example 5
In Burst and Swift Mode, the meter’s functionality is restricted to allow the microprocessor to devote
most of its operation to performing measurement operations. If measuring a single frequency, this
technique will not be need for Burst or Swift Mode data. In Burst or Swift Mode, measurement
correction for Cal Factor is always performed with the SENS:CORR:FREQ ### command. By sending
this command before entering the Burst or Swift Mode from the Normal mode, all subsequent Burst or
Swift Mode measurements will be corrected for that frequency.
The above operation creates a problem if changing frequency during Burst or Swift Mode measurement.
The following program is used to apply correct cal factors to swept or multi frequency measurements
that have been performed during Burst or Swift Modes. In these modes, swept measurement correction
functions are performed in the computer, thus increasing the measurement speed more than would
otherwise be possible. First the Cal Factors are read from the sensor’s EEPROM. Then the Cal Factors
are put through an interpolation algorithm into a correction data array that matches the start/stop
frequencies of the test source and the number of measurement points to be collected during
measurement. Then measurement is performed, and the correction factor array is added to the
measurement data array before being output to a file or swept onto a screen display.
10 ALPHA ON
20 CLEAR SCREEN
30 OPTION BASE 1
40 !
50 DIM Freqs(80),Clfcs(80),Corr_clf(5000),Rdgs(5000),Rdgs_corr(5000)
! These are in REDIMs later in program
60 DIM Id$[90],Err_msg$[70]
70 DIM Ques$[200],Calf$[200]
80 !
90 Tim_per_pnt = 5 ! milliseconds per sample point. Set 1 to 999.
100 !
110 !#########################################
120 ! Instrument ADDRESS ALLOCATION
130 !
140 ASSIGN @Slot0 TO 70100 ! 70100 is Logical Address of the Slot 0
! controller (Resource Manager)
150 ASSIGN @Sweeper TO 720 ! Use normal address for non-VXI instruments
160 ASSIGN @Pwr_mtr TO 70101 ! Power Meter is next to the slot 0 Resource Manager
170 !#########################################
180 !
190 ! Identify Attached Instruments
200 !
210 OUTPUT @Slot0;*IDN?
220 ENTER @Slot0;Id$
230 PRINT SLOT 0 is ;Id$
240 !
250 OUTPUT @Pwr_mtr;*IDN?
260 ENTER @Pwr_mtr;Id$
270 PRINT SLOT 1 is ;Id$
280 WAIT 1
290 !
300 !########################################
310 !
320 ! CALIBRATE THE SENSORS
330 !
340 !########################################
350 !
360 CLEAR @Pwr_mtr
370 WAIT 1
380 OUTPUT @Pwr_mtr;CALC1:MODE NORMAL
! Can ONLY send Sensor Offset
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