User`s guide

Chapter 7 113
Reading/Writing Measurement Data
Retrieving Measurement Results
7. Reading/Writing Measurement Data
The program in Example 7-2 is described in detail below:
Lines 50 to 60 Assigns a GPIB address to the I/O pass.
Lines 80 to 100 These lines set channel 1's active trace to trace 1 and hold the sweep.
Lines 110 to 120 These lines retrieve the number of points in channel 1 and store that
number into the Nop variable.
Line 130 Resizes the Fdata and Freq arrays based on the value of the Nop
variable (the number of points).
Line 170 Sets the data transfer format to binary.
Lines 190 to 200 These lines retrieve the data header.
Line 210 Retrieves the formatted data array for the active trace (trace 1) in
channel 1, and stores the data into the Fdata array.
NOTE Because binary data must be read without being formatted, the program uses an I/O path
(@Binary) that is configured to support the retrieval of unformatted data. This applies to
line 250 as well.
Line 220 Reads the message terminator at the end of the data.
Lines 230 to 240 These lines retrieve the data header.
Line 250 Retrieves the stimulus array for channel 1 and stores the data into the
Freq variable.
Line 260 Reads the message terminator at the end of the data.
Lines 300 to 310 These lines retrieve the data format for the active trace (trace 1) in
channel 1, and store it into the Fmt$ array.
Lines 320 to 450 The lines display each point along with one measured value and a
frequency if the Fmt$ is “MLOG”, “PHAS”, “GDEL”, “MLIN”,
“SWR”, “REAL”, “IMAG”, or “UPH”; or along with two measured
values and a frequency if Fmt$ returns any other string.