Agilent Technologies 4294A, Programming Manual

Page: 63 / 518

Chapter 4 63
Preparing For Accurate Measurement
Fixture Compensation
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Fixture Compensation
To turn on or off the open/short/load compensation of the fixture compensation functions,
use the command given below. You can set open/short/load compensations independently.
However, if no compensation coefficients are retained, the functions cannot be turned on.
• “COMST{A|B|C}” on page 282
To measure open data, short data and load data for calculating compensation coefficients in
open/short/load compensation of the fixture compensation functions, use the commands
given below. Executing these commands calculates fixture compensation coefficients of
measured data and stores them in volatile memory (RAM). In addition, the compensation
function for measured data is turned on.
• “COM{A|B|C}” on page 281
NOTE
User calibration data and fixture compensation data are measured either at fixed points
preset by the Agilent 4294A (fixed measurement points) or at sweep measurement points
set at the time of command execution (user-selected measurement points). In the case of
the former, the compensation coefficient at a sweep measurement point is obtained by
interpolation. To select points for measuring data, use the “CALP” command on page 275.
To set standard values to be used in measuring these data, use the commands given below.
• “DCOMOPEN{G|C}” on page 293
• “DCOMSHOR{R|L}” on page 294
• “DCOMLOAD{R|L}” on page 292
To read open data, short data or load data measured, use the command given below.
• “OUTPCOMC{1-3}?” on page 374
You can calculate fixture compensation coefficients by entering open data, short data and
load data (data read by the above or similar command). To enter data, use the command
given below. Executing these commands calculates the fixture compensation coefficients
of measured data and stores them in volatile memory (RAM). In addition, the
compensation function for measured data is turned on.
• “INPUCOMC{1-3}” on page 321
NOTE
Enter data after setting the standard values used in measuring the data because these values
are needed to calculate fixture compensation coefficients.
NOTE
Enter data after making settings identical to the data measurement points (fixed
measurement points, user-selected measurement points) set at the time when the input data
were acquired. In addition, in the case of the user-selected measurement points, enter data
after making the sweep settings identical to the data measurement points.