Seperate Cycles to Seperate Arrays

[bh3560]

Hello Everyone,

I am testing the friction value of a piece of magnetic tape. The sample passes over a stationary guide with a weight on one end and the other end hooked to a transducer that is moved by a motor. This test will make 8 cycles then stop. I am using a usb-6009 DAQ to acquire the voltage from the transducer. I need to capture each of the 8 cycles separately. The test is graded by the max value of the 1st and 8th cycles. I do not need to keep cycles 2-7. I am thinking of using arrays but I am not sure how I would separate them. I have two possibilities to do this,one I could use a threshold voltage level and second there is a counter that I could receive a pulse at the end of each cycle. I am not sure which way  to go and how to separate the arrays. The counter pulse would be a sure way of separating the cycles vs. a voltage level that could vary enough to be a problem. Any help or ideas will be greatly appreciated. Sorry this is so long of a post, I just wanted you to have enough information to go on. I am using Lab View 7.1 with W2k.

Thanks,

Brett

[Andy F.]

Hey Brett,

It seems like you have a couple of different methods for doing this.  If you do have a method to determine that one cycle ended and another began you could run a while loop inside a for loop and build an 2D array of the data that you would need to analyze.  Once you have the array you could disregard cycles 2 - 7 and then find the max value of the first and last values.  You could also keep track of each value and only keep the highest for runs one and eight.

Please let me know if this is along the lines of what you are looking for or not.  Thanks!
Andy F.

Message Edited by Andy F. on 03-30-2006 05:11 PM