Specifications

128 Chapter 6
Read and Write Measurement Data
Internal Data Flow
Fixture Compensation Coefficient Arrays
The fixture compensation coefficient array contains fixture compensation coefficients in
the complex format. These were calculated using a fixture compensation data array. As
shown in the following table, there are three arrays containing fixture compensation
coefficients A, B, and C.
Use the following GPIB command to read or write a fixture compensation coefficient
array.
• DATA:CMP{1-3} on page 348
When the sweep type is set to segment sweep, use the following GPIB command to read or
write a fixture compensation coefficient array.
• DATA:SEGM{1-16}:CMP{1-3} on page 353
NOTE Before writing all of the fixture compensation coefficient arrays, set the measurement
frequency and oscillator level to the same values specified when they were read and enable
the fixture compensation function. Note that if fixture compensation is disabled, it cannot
be enabled until Open/Short fixture compensation data is measured. Therefore, fixture
compensation data must be measured before fixture compensation coefficient arrays are
written. However, measuring actual fixture compensation data is not necessary.
Accordingly, you can measure fixture compensation data without connecting a fixture
compensation standard and then enable fixture compensation.
After performing measurement using the written fixture compensation coefficient arrays, if
stimulus values are changed, or if fixture compensation is switched between enabled and
disabled, the fixture compensation arrays are written again, resulting in incorrect
measurement regardless of whether fixture compensation is enabled or disabled.
Timing for read/write
When a read command is executed during a sweep, the data at the time the command is
executed is read. Therefore, in order to obtain correct measured data, it is necessary to
execute the command for data read after waiting for the completion of the sweep. In cases
in which the program execution speed is considered, the read command should be
synchronized with the completion of the sweep and executed upon its completion. In order
to synchronize with the completion of the sweep, use the status report system. Refer to
“Example Programs for Detecting Measurement End” on page 114 for details.
Array
number
*1
Contained data
1 Fixture Compensation coefficient A
2 Fixture Compensation coefficient B
3 Fixture Compensation coefficient C
*1. This number corresponds to the number specified at the end of the com-
mand.