HP 8590 E & L Series Spectrum Analyzers and HP 8591C Cable TV ...

Different Formats for Trace Data Transfers
Two different ways to format trace data using the TDF command were introduced earlier in
this chapter (TDF P and TDF B). This section describes all the available trace data formats.
The HP 8590 Series spectrum analyzer provides five formats for trace data transfers: real
number (P) format, binary (B) format, A-block format, I-block format, and measurement units
(M) format.
P Format
The P format allows you to receive or send trace data in a real-number format. This is the
default format when the instrument is powered up. Numbers are in dBm, dBmV, dBpV, volts,
or watts. The AUNITS command can be used to specify the amplitude units. Real-number data
may be an advantage if you wish to use the data later in a program. However, data transfers
using P format tend to be slow and take up a lot of memory (compared to binary format, the P
format can take up to four times the amount of memory). Data is transferred as ASCII type.
Although the spectrum analyzer can send the trace data to the computer as real numbers, the
trace data cannot be sent back to the spectrum analyzer without changing the trace data to
measurement units (integers). See the following example.
3-20 Programming Topics