Too much values in daq recording

[Hulk1978]

Good morning,

i improved my small datalogger to event struct. But something is wrong. I´m getting too much values.

I only reading two analog channels but i´m getting many twice values.

Unfortunately i cannot understand the reason.

[PalanivelThiruvenkadam]

HI Hulk1978,

You are keeping the Valued in Shift Register which will hold the previous Value.

[Hulk1978]

Oh.This means labview copy with every iteration this array new to spreadsheet?

But i need an array for the write to spreadsheet. Actually i didn´t found another solution

[PalanivelThiruvenkadam]

There are two ways to do.

1. Keep the data in an array and Log to File before Exiting the Application.

2.Just use build  array Function to match to your Spreadsheet Function Input node.

[crossrulz]

You could just use the Export Waveforms To Spreadsheet File.vi to do your logging.  It will do pretty much everything for you.  Your data rate is slow enough you will probably be fine despite it constantly opening and closing the file.

When it comes to DAQ data, my first preference is to use the DAQmx Configure Logging to stream the data to a TDMS file.  My second preference is to use a Producer/Consumer, where you have another loop that does all of the logging.  This helps to make sure you are keeping up with the DAQ.

[Hulk1978]

Good morning,

i actually changed style to put array directly to "write to spreadsheet" and it works fine

For my loggings i only need sample rates between 6 and 10Hz. So i was not sure if i need a third loop for production.

To use TDMS i´m afraid to need special viewer. Actually i don´t have budget for additional software. But i know the disadvantage of limitation with excel

[GerdW]

Hi Hulk,

---

@Hulk1978 wrote:

To use TDMS i´m afraid to need special viewer. Actually i don´t have budget for additional software. But i know the disadvantage of limitation with excel

---

LabVIEW comes with a TDMS plugin for Excel (no additional fee), so Excel will read TDMS files as well…

[crossrulz]

---

@Hulk1978 wrote:

To use TDMS i´m afraid to need special viewer. Actually i don´t have budget for additional software. But i know the disadvantage of limitation with excel

---

If only somebody made a TDMS viewer that was free...Scout by Signal X.  I used that tool in a few previous positions.  It was really well done.

[Hulk1978]

Hello everyone,

i tested the excel addin and scout. Scout looks a little bit better.

Additional i added a third loop for production. It works well.

But i produced one more failure. I hope it´s small.

For every pushing start button for recording i want to create a new file. To separate it i mixed filepath with timestamp. Now i wanted to sent the path from event to consumer with a notofier.

But i´m getting most of time error because of non existing path. Sometimes it works (confirmation repeat at failure message). 

[GerdW]

Hi Hulk,

---

@Hulk1978 wrote:

Now i wanted to sent the path from event to consumer with a notofier.

But i´m getting most of time error because of non existing path. Sometimes it works (confirmation repeat at failure message). 

---

Race condition alarm!

You are writing to several notifier/queues in parallel. You are reading several notifier/queues in parallel. Which one is processed first?

You need to make sure all data is valid before you start to open a new TDMS file…

Suggestion: instead of using two notifier (for enum command and file path parameter) you should use only one notifier, transporting a cluster of [enum, filepath]. Now you can be sure to receive related items within one cluster. (Leave the filepath empty for other commands than "Start recording")…