Specifications

120 Chapter 6
Read and Write Measurement Data
Data Transfer Format
Data Transfer Format
When a measurement condition setting is read from the E4991A, for example, when the
FREQ:STAR command in the query format is used to read a sweep start frequency value,
the ASCII format is used regardless of the data transfer format setting.
On the other hand, when simulation results of frequency characteristics are read during
data measurement or equivalent circuit analysis, for example, when the
CALC{1-5}:DATA? command is used to read a data trace array, either the ASCII (default)
or binary format can be used. The binary formats include IEEE 32- and 64-bit floating
point formats. Depending on the controller used, choose the appropriate format. Use the
following GPIB command to select a data transfer format. When the binary format is
selected, byte transfer order (byte order) can be specified.
FORM:DATA on page 374
ASCII Format
When data is read in the ASCII data transfer format, numeric values are transferred as
ASCII bytes in one of the following formats. They are delimited by commas (,) in
accordance with the IEEE488.2 specifications.
NOTE Strings representing numeric values vary in length. Therefore, when each string is read
from a comma-delimited list, commas do not appear in fixed positions.
Integer Format
Figure 6-1 shows the integer format. A numeric value is represented as an integer. For
example, a numeric 201 is expressed as “+201” or “201”.
Figure 6-1 Integer Format