Sample Rate is slower than expected

[n12iki]

Hi

I am trying to sample the temperature off of RTDs using a NI 9226 module with a cDAQ 9184. The module should support about 50 Hz if you use 8 channels according to its manual. It seems like the cDAQ should also be able to support this frequency, but Im not 100% sure. Currently when I run my vi file I only get a new temperature reading once every 2 seconds.  I cant tell if this is due to my code or if I misread something and one of the devices cant handle the frequency that I am asking it to do. If I run only one channel the it is at about 10Hz, which I also find odd since it should be able to work much faster than that. Thank you for the help

NI model datasheet http://www.ni.com/pdf/manuals/376922c_02.pdf

cDAQ datasheet http://www.ni.com/pdf/manuals/372087a.pdf

[crossrulz · Accepted solution]

You have the device configured to "High Resolution".  According to the data sheet, in high resolution mode you will get a full scan every 1.6 seconds.  One channel should be 200ms (5Hz).  To go faster, in your DAQ Assistant under the Configuration tab is a Device tab.  Go there and change the ADC Timing Mode to "High Speed".

Also, no need for the wait in your loop since the DAQ will be limiting your loop rate.

[n12iki]

Thank you that fixed it