Instrument Control (GPIB, Serial, VISA, IVI)

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HP4284A Frequency Sweep with frequency points read from a tab delimited excel or lvm file

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I am using a HP4284A, and have downloaded the file here. However, I cannot figure out what format of file it takes as input: I understand this should be a .lvm tab delineated value file, but in what order is the data? If someone could provide an explanation, or an example data file, I'd greatly appreciate that.




Ps. I know the linked article says that 'The frequency points are as defined for the oscillator in the HP4284A user manual.', bit I have been through the manual from end to end, and I can't find anything of the sort. The closest I've been able to find is the codgin for remote access, but that isn't very relevant as Labview and the coding (C++, I believe) used are very different.

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Message 1 of 12

That VI simply reads in the file and converts it to an array of frequencies. The file can simply be a single column where each row corresponds to a frequency:








I have no idea why the writer chose to use Read From Measurement File, since no timing information is being used. A much simply approach would have been to use Read From Spreadsheet File.

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Message 2 of 12

Hm. I should have elaborated on what I had tried.


I have tried:






In which case, it only reads frequency 3.


Freq1 [tab] Freq2 [tab] Freq 3...


In which case, it only reads frequency 1.


Other than this, what else can I try?

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Message 3 of 12
Accepted by topic author Firnagzen

Figured it out. There's a problem in the block diagram, the stop condition is wired wrongly. It's wired so that when the input frequency from the list is less than 1MHz, it stops. It should be the other way around.

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Message 4 of 12



I still could not find the problem. Can you send me your final vi file?





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Message 5 of 12

Simply right click on the conditional terminal of the while loop and change the stop behavior. You only have two options so it's very easy.

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Message 6 of 12



I already have done that, and the aquisition is working well except when it reach1 Mhz it does not stop. Still is a progress..





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Message 7 of 12

Did you change it for the inner or outer loop?

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Message 8 of 12

Sure. I wound up adding some additional features to it, though, badly. It's perfectly functional but badly coded (veteran users please don't laugh); I could probably optimize it now, having learned more, but I'm too lazy to. There's a writeup, too.

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Message 9 of 12

Tks guys for the discussion. It really help me with my project.


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Message 10 of 12