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How to get the actual generated frequency using a arbitary FG (5422) in standard function mode?

For arbitary FG the standard function genration is realized in software. (5422 in my case)

Assuming it does the best the NI programmers realized, it's clear that the frequency generated will be coerced at a certain point. (But the actual generated frequency is known... somewhere 😉 )

 

Is there a way (or property) to read or calculate the actual generated frequency? 

(knowing the actual wfrm size and actual samplerate would be a strong indicator)

Just like the actual samplerate, that could be different to the user entered arbitary samplerate.

 

 

Greetings from Germany
Henrik

LV since v3.1

“ground” is a convenient fantasy

'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'


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Reading back a property should return the value actually used by the driver (aka "coerced" value). This is true for most properties on most of our drivers including NI-FGEN. Let me know if the NI-FGEN driver does not return coerced value for this property for this device model.

 

That said, this is calculated with the assumption that the VCXO on the hardware is a perfect (200 MHz for that instrument if I recall correctly). You can minimize the error by providing your own higher quality clock or using the device's PLL to lock to a higher quality base clock.

 

Good luck!

Marcos Kirsch
Chief Software Engineer
NI Driver Software
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Thanks for the quick answer, i will give it a try.

In this case the most important part is the strict locking of the 5422 FG and the 5922 scope in one PXI system incl a 6652 or 6672 timercard in the rigth place, usually locked to our 10MHz time distibution based on Cs Clocks (working in an NMI)  😉

 

Using the standard wfrm mode is the lasy way.

 

 

Greetings from Germany
Henrik

LV since v3.1

“ground” is a convenient fantasy

'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'


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