Agilent Technologies 4294A, Programming Manual

Page: 98 / 518

98 Chapter 7
Processing Measurement Results
Reading Measurement Data at Specific Measurement Points (Using the
Marker Function)
Reading the marker-specified value
Use the following commands to read the marker-specified measurement or sweep
parameter value.
You can use the following command to display a list of all marker-specified values on the
Agilent 4294A LCD. Note, however, that you cannot use these commands to read these
values.
• “MKRL” on page 352
Sample program for using the marker function
Example 7-1 shows a sample program for using the marker function. This program is
available under the filename of “marker.bas” on the sample program disk.
This program performs sweep once, uses the marker function to search for the maximum
peak and the minimum negative peak in the 10-100 MHz range, provides a submarker at
each of these peaks, and reads and displays the submarker-specified values.
Lines 30 to 70 Identifies the external controller and Instrument BASIC and sets the
GPIB address.
Lines 90 to 110 Substitutes the lower and upper border values for the search range and
the trace selected as the active trace into the corresponding variables
Sear_min$, Sear_max$, and Act_trc$, respectively.
Lines 130 to 160 Resets the Agilent 4294A, performs a sweep once, and waits for the
sweep to be completed.
Lines 180 to 190 Sets the trace selected as the active trace to Act_trc$ and executes the
auto scale to automatically set the scale parameters so that the
waveforms fit on the screen.
Lines 210 to 240 Turns ON the marker and sets the lower and upper border values for
the search range to Sear_min$ and Sear_max$, respectively.
Lines 260 to 300 Defines the peak by specifying “0.1/1e6” and “positive” as peak slope
threshold and peak polarity, searches for the peak and moves the
marker to that peak, and positions submarker 1 at the peak.
Lines 320 to 340 Redefines the peak by specifying “negative” as peak polarity, searches
Measurement Parameter
Value
Supplementary Reading for
Measurement Parameter
Value (Vector)
Sweep Parameter Value
Marker “OUTPMKR?” on page 387
“MKRVAL?” on page 360 “MKRAUV?” on page 351 “MKRPRM” on page 358
Used for query
Submarker “OUTPSMKR{1-7}?” on page 393
“SMKRVAL{1-7}?” on
page 441 “SMKRAUV{1-7}?” on page
438 “SMKRPRM{1-7}” on page 440
Used for query
Δ
Marker “OUTPDMKR?” on page 377
“DMKRVAL” on page 306
Used for query
*1
“DMKRAUV” on page 303
Used for query
*1
“DMKRPRM” on page 305
Used for query
*1.You can read parameter values only when you use the fixed
Δ
marker.