Programmer’s Guide 6-3
Trace Data Transfers
Querying the Measurement Trace Using BASIC
Querying the Measurement Trace Using
BASIC
After making a measurement, you can read the resultant measurement
trace out of the analyzer using the SCPI query:
"TRACE:DATA? CH1FDATA"
The BASIC program segment below shows how to read the trace from
the analyzer into an array in your program.
10 REAL Trace(1:201)
20 ASSIGN @Hp8711 TO 716
30 ! Take sweep here
40 OUTPUT @Hp8711;"FORM:DATA ASCII,5"
50 OUTPUT @Hp8711;"TRACE:DATA? CH1FDATA"
60 ENTER @Hp8711;Trace(*)
70 DISP Trace(1),Trace(2),Trace(3),"...."
In this program, the TRACE:DATA? query returns all of the
measurement points as a single block. The analyzer computes the value
for each point using the measurement format selected by the [FORMAT]
menu (CALC:FORM SCPI command), and returns a block of data called
the formatted data array. The values of each point correspond to the
values displayed on the screen, or those shown in the marker readouts.
The frequency stimulus value (X-axis) of each point is not returned by
the TRACE:DATA? query; only the measurement response (Y-axis) values
are returned.
When transferring the block of trace data, you may select either binary
or ASCII data encoding. This is explained in Chapter 4, “Data Types and
Encoding,” in the section titled “Data Encoding for Large Data
Transfers” on page 4-6. Notice that the terms "encoding format" and
"measurement format" are not the same. The encoding format
determines how the numbers are represented as bytes, while the
measurement format corresponds to the meaning of the value of the
numbers.
The easiest way to transfer a measurement data trace is to use ASCII
data encoding.
To Next Page
Loading...
Need help?
General
