change the sampling rate

[vishal231]

Hello,

1. I am using Crio 9047 as chasis ,NI9222 for current measuremnt and other module for other measurement

I am measuring acceleration, current, tempreture , voltage , but value of current i am getting on LabVIEW through Create channel Daqmx block and when Monitord it is not proper ,it is in macro Digits though my current is in 30 and 1000 Ampere range.

I am using rogoswki coil as current measurement. 

100 millivolts equivalent to 1 Ampere( for range of 3000 ampere)

1 millivolts equivalent to 1 Ampere( for range of 3000 ampere)

2. I can store current data ? or how can i empty my Queue when I am not using it.

My data acqusition  Keeps on running but, when i want to record data i get old data in my file(takes data and record data just below from where it recorded last time though,i am running acquistion at other time)

I did added time out in streams and even in Queue but it did not worked , is it not what it should be doing?

3.Also,i am have 5120 samples per channel and storing These in text file  using Array to spreadsheet string but a emply line at every 5120 samples is getting stored and I am having emplty linees in my file. how to remove that single empty line?

4.I want to chnage the sampling rate, Right now sampling rate is 51,200 though I  have kept 50,000 as rate in sample Clock. how can I chnage the rate?

Below are my VIs 

Regards

Vishal 

[vishal231]

below is the rogswski sensor Picture 

[vishal231]

I am having the same issue ,

1.getting the a blank line at end of the each samples of strings.

2.also, space get created before first string after getting a sample of string

attached scrrenshot

doing data acquistion and data logging and saving to text file 

attached VIs

Regards

Vishal

[vishal231]

hello,

Doing data acquistion and data logging and saving to text file 

1.getting the a blank line at end of the each samples of strings.

2.also, space get created before first string after getting a sample of string

attached scrrenshot

3. also, not getting proper current value from create channel DAQmx , what should be Minimum and maximum value to be set ?

do I have to do custom scaling? I am using rogoswki proble for current measurement,NI 9222 module and LabVIEW 2018 (see the picture)

attached VIs

Regards

Vishal

[vishal231]

Hello,

I  am using Crio 9047

I want to Change the sample rate but ist not changing  .

when i put rate as 50k it samples at 51.2k S/s ,

when i put rate as 34.13k it samples at 47.8k S/s ,

On board Clock selected , i tried other master frequency eg 13Mhz(cRIO-MAKSIM/13.1072MHzTimebase) and 12Mhz , it Shows error 200414

Why it is not chaging as i want ?

VI attached 

[GerdW]

Hi vishal,

please stick with your thread instead of creating new ones again and again!

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@vishal231 wrote:

when i put rate as 50k it samples at 51.2k S/s ,

when i put rate as 34.13k it samples at 47.8k S/s ,

On board Clock selected , i tried other master frequency eg 13Mhz(cRIO-MAKSIM/13.1072MHzTimebase) and 12Mhz , it Shows error 200414

VI attached 

---

Unfortunately you didn't attach any VI this time, so I comment on that older "aq.vi"…

You read several channels from several modules: which modules do you use? Which sample rates do those modules support? Did you read their manuals/specsheets?

You surely talk about error -200414 (mind that minus sign!): did you read the error explanation? It's pretty clear…

[vishal231]

Hello Gerd,

Yes , I read the data Sheets of the modules

NI 9231 : 51.2kS/s(max)

NI 9222: 500kS/s(max)

NI 9216:400S/s(max)

NI 9244: 50kS/s(max)

for only NI 9231 Details for sampling rate is given , its in discreate form , a table is given of available rate master timebase frequency.But , These rates are different from the rates i am getting when I am doing data acquistion.

I want to know which rates my program is using?where I can find it?I want to chnage the rate according to me,can I do that?

even what is meant by OnBoard Clock?

when its given for moudule NI 9231 that I can use master frequncy timebase (13Mhz) but, I am not able to chnage it.

Regards

Vishal

Regards

Vishal Kaushik

[vishal231]

one more Thing, my source in DAQmx Timing is OnBoard Clock selected

[GerdW]

Hi vishal,

what happens when you create one DAQmx task per module?

[vishal231]

Hello Gerd,

I created different Tasks for different analog Input and connected each Task one by one and found out that

NI 9222 : works with specified sampling rate

NI 9231 and 9244(acceleration and voltage 😞 gives different rates eg, if specifies set rate to 1k S/s it gives 1477 S/s.

I made a Task which had all the analog inpurts including NI 9216 :  if rate set to 1k it gives 1724 S/s

Please tell how to set requierd sample rate? if ist possible or not?

Regards

Vishal Kaushik