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NI 9263- NI9269 precision

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Hello,

I have just one question . How the ni9263 and ni 9269 could have the same number of bits (n=16), the same level voltage (+/-10V) and a different precision (9263: 0.11V / 9269: 0.006V)?

I think that precision of signal depends on resolution and resolution =V/2^n. Now why the precision is different?

 

thanks

regards

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Message 1 of 11
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You are talking about resolution 😄

 

Range does not have to equal the max ADC range 😉

 

Precision ?  What is pecision???   I usually talk about uncertaincy tied to a measurement 🙂

 

And uncertaincy usually is a function with a lot of (statistic) variables.

 

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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Message 2 of 11
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Hi ,

thanks for your answer.

And for precision , look at  the NI specification : http://sine.ni.com/nips/cds/view/p/lang/fr/nid/208806. We note that precision is egal to 0.11V.

thanks

 

 

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Message 3 of 11
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Solution
Accepted by topic author new_ingenieur

So you found out that the number of bits doesn't tell you all 🙂

The resolution of the DAC isn't all. It needs the DAC, a reference source (build-in or external), a supply and an amplifier, all build on a PCB in a housing.

Every part plays a role to the uncertaincy/precision, common main enemies are temperature, drift (over time and temperature), humidity ....  EMC/noise/....

And, no wonder.... one part is about twice the cost of the other.

 

You can buy a resistor for less than 1c or >1000 times that value ...  both migth have the resistance ... well, at a certain point ...

 

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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Message 4 of 11
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************************thanks for answer.Now it's very clear****************************

 

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************************thanks for answer.Now it's very clear****************************

 

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Message 6 of 11
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Normally i know that i must open a new topic for ask question. But i need this response very quickly it's a high importance.

Tell me if NI9263 could have an offset value? i buy it just one year ago and  i don't see 'offset' in specification.

I ask this question because i have ni 9263 + electronic circuit. On my output i have an offset .

thanks

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Message 7 of 11
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on page 13 I see an offset error spec.

uncalibrated 1.7% of 21.4V ...   so you migth expect up to 364mV Offset in the temprange -40 to +70°C

 

Don't know this hardware... is there a autocal or selfcalibration button in MAX?

 

 

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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Message 8 of 11
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hi,

May be in max there are this button but i don't see them. But now What worried me , it's this value of offset .Its very high for my measure.

I have a signal of 220mV so offset egal to 364mV is very high for me.

 

Do you have tips for this?

 

regards

 

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Message 9 of 11
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How about doing an offset cancelation befor starting your application?

Measure the offset and include that value in your setpoint?

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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Message 10 of 11
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