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N9912A Cable Data File Format?

Question asked by JohnAckermann on Mar 1, 2019
Latest reply on Mar 7, 2019 by JohnAckermann

Is there any documentation or file format information available for the cable definitions files used in the Fieldfox 9912A CAT application?  I haven't been able to find anything on the web.

 

I used an existing cable file from the Fieldfox as a template on my PC and created new files with new names, then copied the new files into the Cables folder on the Fieldfox.  They show up in the list when I hit "Recall", but when I select one I get this error: "Cable Type File Not Found."

 

I'm guessing I have the syntax messed up, so would like to find something that defines things like:

 

1.  The relationship between the .xml filename, the <Name>, and the <Description> fields, and what characters are valid. (e.g., I named my file LMR240-N8UR to differentiate it from the original.  Is that valid?  Are spaces allowed in any of the fields?)

 

2.  Is the XML <!-- comment --> structure recognized in a cable definition file?

 

3.  How the <PropagationVelocity> field is calculated -- the existing files probably have more precision than is meaningful, and that precise number used doesn't relate back to any value that I can find for the speed of light.  For example, the LMR240 file has the velocity set at 251 825 665 (presumably meters/second).  If the velocity factor in percent is 83, which is what the Times Microwave data sheet says, that puts C as 303 404 415 m/s, when the real value is 299 792 458.  83 % of that is 248 827 740.  In reality, it's nuts to use that kind of precision given the tolerance of the VF value, and the rounding that I'm sure goes on in the application.  So I'd like to use, e.g., 249 000 000, the rounded value based on the definition of C.  (Note -- I inserted spaces here for clarity; they're not in my xml files!)

 

4.  Is there a limit to the number of <Frequency><Loss> pairs that can be used in a definition -- most of the default ones have only one or two; I added the full range from the Times datasheet, which makes 10.

 

5.  Are there any rules about whitespace in the file or its fields?

 

Sorry for being long-winded, but I'm hoping someone can point me to a source that defines the cable file format and gives clues about these questions.

 

Thanks!

John

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