The Citifile Header; An Array Of Data; Citifile Keyword - HP 8719ET Reference Manual

Understanding the CITIfile Data Format
The CITIfile Data Format
The CITIfile Header
The header section contains information about the data that will follow. It may also
include information about the setup of the instrument that measured the data. For
example, the header may include information such as:
• CITIfile version number
• Network analyzer model number
• Firmware revision currently installed in the analyzer
• Type of Data
• Data Format
• Measurement parameters
• Start and stop frequencies
• Number of sample points
The CITIfile header shown in Example 1 has just the bare minimum of information
necessary; no instrument setup information was included.

An Array of Data

An array is numeric data that is arranged with one data element per line. In the Smith
chart and polar formats, the data is in real and imaginary pairs. In all other formats, the
data is still in pairs, but the second term of the pair is 0E0. All information is true
formatted data in the same format as on the analyzer display (dB, SWR, etc.).
A CITIfile package may contain more than one array of data. Arrays of data start after the
BEGIN keyword, and the END keyword will follow the last data element in an array. A
CITIfile package does not necessarily need to include data arrays; for instance, CITIfile
could be used to store the current state of an instrument. In that case the keywords VAR,
DATA, BEGIN, and END would not be required.
CITIfile Keyword
Keywords are always the first word on a new line. They are always one continuous word
without embedded spaces. A listing of all the keywords used in the latest A.01.01 version
of CITIfile is shown in "CITIfile Keywords." When reading a CITIfile, unrecognized
keywords should be ignored. This allows new keywords to be added, without affecting an
older program or instrument that might not use the new keywords. The older instrument
or program can still use the rest of the data in the CITIfile as it did before. Ignoring
unknown keywords allows backwards compatibility to be maintained.
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