DAQ Assistant issue

[mkatsiou]

Hello,

A few months ago I created this program that reads two channels, records them on a table, graphs them, and has a live readout of what values they have.

My issue is that if I set the DAQ Assistant to read continuous samples and read 100 samples at 200 HZ, the DAQ Assistant seems to reset my device every time it runs through those 100 samples (ex: the data will read 100,101,100,99,100,0,10,20,30,40,50,60,70,80,90,100,...). If I turn up the same reading to, say, 1000, then i have less of these "resets" (although it still happens every 1000 readings), but then my live readouts only update every 10 seconds.

[RavensFan]

Please do a Save for Previous Version and save as LV 15 or older and upload that.

You used LV 16 which just came out a month ago.  Not everyone has installed it yet.

[mkatsiou]

Sorry, Here ya go.

[mkatsiou]

Sorry about that, Here you go.

[RavensFan]

The first problem I see is that you have two DAQ assistants in there.  One not connected to anything.  They have different signal names, but they point to the same hardware channels.

The second problem I see is that you convert the blue dynamic datatype wires to double arrays thus discarding all of your timing information.  Thbat means you have to wire values into the butterworth filters for frequency that don't match the actual frequencies of the data you are looking at.

[mkatsiou]

The second DAQ Assistant was just me experimenting and I forgot to delete it, I am not using that for anything.

As for the datatype conversion, I'm not sure I fully understand the issue. When I convert from the blue to orange I lose the timing? Is there an alternative way for me to filter the data without converting it?

[mkatsiou]

So here's a file where I've removed the second DAQ Assistant and removed the data conversion & filters, which, strangley enough seems to give smoother data than with the filters.

My issue now is that the DAQ Assistant (or something) seems to be resetting every 10 seconds or so and the data will go from positive to negative, for example: 101,101,101,55,10,-20,-60,-102,-102,-102.

EDIT: After playing with it more it seems that the data is smoother because it is no longer communicating with the sensors...

[RavensFan]

Obviously if you have problems now communicating with sensors, you'll have to fix that.

But I'm confused by you saying your values are going from positive to negative.

What exactly do you have connected to your DAQ card.  (I know you say you are reading Load Cell and Deflection, but what are the actual devices reading these?)  Where do you see these values of 100 +, on load cell, on deflection, somewhere else?

[mkatsiou]

Well, I am using a Force Transducer and string potentiometer to measure the load/deflection on a pneumatically controlled strut. Once I deleted the section with the filters and data conversions the sensors no longer seem to be communicating with the DAQ Assistant. But, while the program is running (and not receiving anything from the sensors) the load cell readout will display 104 for a few seconds, then slowly work its way down to -102, stay there for a few seconds, then back up to 104. The string potentiometer's readout will act similarly, but it will go between 10.3 to -10.1

[mkatsiou]

Alright, I found that I had broken a cable and the signal wire was contacting the power supply, so the unit was getting a steady 10.4V (multiplied by my 10x scale, gave me 104 readout). 

With the cable fixed, the second DAQ Assistant removed, and the data conversion & filter removed, I am still having the original issue where the unit or the DAQ assistant resets after the DAQ assistant's sample amount runs through.