Need some Help Urgent!!!

[sai321]

Hi, 

I made a VI to record some sensor data in my experiment and i am trying to acquire 512 data points in a period of 1sec but when i am trying to write the data to excel file in labview. it's recording 512 data points in less than 1 sec. it's not taking complete second. if i do a simple VI with only one sensor directly and writing it to the file then it's recording 512 data points in a time of 1sec. 

I am using cDAQ9172 and NI9237 and NI9205 modules 

Note: attaching latest version VI and compatible version VI

Thank you in advance

[RavensFan]

How do you know it is less than a second?  How long does it take?

According to the data sheet for the NI-9237, the minimum data rate is 1.613 kS/sec.  Much faster than 512 Hz.

http://www.ni.com/pdf/manuals/374186a_02.pdf page 9.

[crossrulz]

How exact do you need that 512Hz?  With a minimum sample rate of 1613S/s, you could average 3 or 4 samples at a to effectively reduce your sample rate to 537.7Hz or 403.25Hz respectively.

[sai321]

It's not mandatory for me to take 512 data points. I am just confused with number of samples to read and sample rate. I just wanted to use both as same number in order for simpler calculations. If 9237 is 1.613ks/s what about 9205 ?

[RavensFan]

http://www.ni.com/pdf/manuals/374188a_02.pdf

[sai321]

I am sorry i am new to LabVIEW and I am trying to learn step by step. So the frequency of 9205 is 250ks/s and 9237 is 1.613ks/s so considering both can I use 2048 in samples to read and 2048 in sample rate. Will that solve my issue ?

[sai321]

Hello guys i figured out the issue because i am using 9205 and 9237 modules for different sensors. i am facing that timing mismatch. Can any one guide me if i can implement them separately using 2 daqmx ? 

[crossrulz]

Apparently not with that chassis.

You really need to learn to read manuals and specifications. cDAQ-9172 Specifications (page 20).

[sai321]

Yes I read the manual after replying to the post ☹️

[BowenM]

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@crossrulz wrote:

You really need to learn to read manuals and specifications.

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Reminds me of the old response:  "RTFM"  (Read the Fine Manual)