Agilent Technologies 4288A, Руководство по программированию

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66 Chapter 6
Reading Out Measured Result
Reading Out Measured Result
Reading out measured result using
:FETC?
command
You can use this readout method when you want to trigger the instrument from any source
other than an external controller or when you want to perform a process that is between
triggering the instrument and reading out the measured result.
The readout procedure using the
:FETC?
command is described below.
Step 1. Set up the trigger mode as necessary.
Step 2. Trigger the instrument by using the method for the trigger mode.
NOTE To trigger the instrument from an external controller in this procedure, use the :TRIG
command on page 195.
Step 3. Execute the
:FETC?
command at the completion of the measurement.
Step 4. Read out the measured result. To repeat the measurement, repeat Steps 2 to 4.
Example 6-3 and Example 6-4 show sample programs using the
:FETC?
command.
Example 6-3 is for the ASCII transfer format and Example 6-4 is for the binary transfer
format. These programs are stored on the sample program disk under the filenames
“fetch_a.bas” and “fetch_b.bas.”
These programs, when an external trigger is inputted and the measurement finishes, read
out the measurement status, measured primary parameter result, measured secondary
parameter result, and comparator sorting result (when the comparator function is ON) and
display them.
The program of Example 6-3 is detailed below.
Line 60 Sets the GPIB address.
Line 70 Sets the data transfer format to the ASCII format.
Lines 90 to 100 Turns ON the trigger system continuous startup and sets the trigger
mode to the external trigger.
Lines 120 to 130 Reads out the ON/OFF state of the comparator function and assigns it
into the Comp_flag variable.
Lines 170 to 210 Makes the setup generate an SRQ when measurement finishes and
clears the status byte register and operation status event register.
Lines 250 to 260 Sets the branch destination of the SRQ interrupt and enables the SRQ
interrupt.
Lines 270 to 280 Displays the message to prompt the user to input an external trigger
and then waits until the external trigger is inputted and the
measurement finishes.
Line 300 Executes the measured result readout command (
:FETC?
).
Line 320 If the Comp_flag value is 1 (the comparator function is ON), reads out
the measurement status, measured primary parameter result, measured
secondary parameter result, and comparator sorting result.
Line 340 If the Comp_flag value is not 1 (the comparator function is OFF),
reads out the measurement status, measured primary parameter result,
and measured secondary parameter result.