Labview fpga data logging not fully Working

[iapetus2001]

Hi, I just ran the datalogging example for CRIO and Labview FPGA/RT and it worked, but I'm measuring a DC value and it's getting fluctuating measurement. Please, how can I improve this? solve, I mean...

Thanks for your help! I'm a newbie!

[KateB]

Change from chart to graph.

[iapetus2001]

I can't try right now, but i think it won't work. I reviewed the log file and it's supposed to be at 6.30V DC (Agilent high accuracy power supply), and I have top value of 6.30 but lower points. Settling time maybe? I'm using a sampling rate of 1ms, that's slow for this equipment so I may be doing something wrong...Nevertheless, thanks for your help...I'd try it...but please tell me what else i'm doing wrong. Bye!

[MikeeB]

Hi 

From looking at the code you are only interested in one channel and sending data back from the FPGA on all 4. Put an Index Array function in to take the column of your data for channel 0 and only display that. I think that your are getting 500 samples but 125 from each of the four channels. To check ground the other three channels and you should then see 6.3V, 0V, 0V, 0V, 6.3V .....

Mike

[iapetus2001]

Hi Mike, thanks for your answer I worked on what you said and it worked..Thanks for your help! I really appreciate it....sorry for my delayed comment, but I've been with a lot of work and my labview practicing sessions were sadly left behind, nevertheless I tried what you told me just after you told me and it worked....

BUT, there's something going on...If I fix the sampling rate to a 500us, it's not the actual SR......It's less than that, I noticed this using a function generator and making a freq sweep manually to look for the max freq it was able to catch...it was less than 1kHz which is more than 1ms.

What am I doing wrong? is it because I'm using my PC to graph? how can i fix this? Thanks in advance....

[iapetus2001]

I'm getting really interested on this...I hope to have my own answer tomorrow...but please feel free to make any comment...i'd really appreciate it...

[UserLab]

Add 1Mohm resistor from negative to ground. It will work!