02-20-2009 12:02 PM
I am using a simple Labview program that is a simple Do While loop that gets a signal from a Fieldpoint AI module using a FP1601 ethernet communications module. The signal is changing at a rate of 50 ms or so but I cannot get the program to read it quickly. I am using a Wait Millisecond to control the speed of the acquisition and for some reason I can not get the data from the Fieldpoint module faster that approximately 0.7 seconds, even if I put 50 ms as the Wait Millisecond. I tried to change the acquistion time of the AI module (it is at 10 ms) but this doesn't help.
02-20-2009 12:43 PM
Which AI module is it?
02-20-2009 02:39 PM
Thanks for your response, I have an AI-110. I had just switched the filter to 500 HZ on all the channels and now the rate is much faster; however, the reading I am receiving from the fieldpoint module is much noisier than the actual signal from the sensor (read with a Fluka voltmeter).
It appears that the 60 Hz is too slow and the 500 Hz is too fast. Can you recommend some type of VI filter that I could use. I think I will try a moving average filter.
02-20-2009 03:46 PM
Hardware filter setting was my hunch.
Be aware the Fluke may be performing averaging internally and have a slower response time, thus your Fieldpoint data may be real. The only way to know for sure is to hook up an oscilloscope to the device.
Can't suggest any specific filtering, it may depend on the nature of the 'noise'