Re: Determining Voltage Rate of Change
Process Systems <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > The number of samples is irrelivent. The delta-T is derived from the > sampling rate. In this case, 1000 HZ sample rate corresponds to 1 ms. > delta-T. > > Good luck. > > Dave Hmmm...I've wired it up, but it looks like the output of the derivative VI is an array of the size of the number of samples. And it's producing nonsense values. If the voltage was constant, I would expect the derivative to be zero for example. Adjusting the voltage up would produce a positive scalar, and adjusting the voltage down would produce a negative scalar. How do I convert the output array into a meaningful scalar value? I can provide my current vi if you need to see it..my email is [EMAIL PROTECTED] thx Jeff
Re: Determining Voltage Rate of Change
Process Systems <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>... > Take a look in the Functions/analyze/signal processing/time domain and > select the Derivative x(t).vi. This should do the trick for you. > > Good luck. > > Dave Looks promising! So, given 100 samples to read at 1000Hz, acquiring continuously..what would my dT be?
Determining Voltage Rate of Change
In my VI, I need to set a digital line if the measured input voltage changes too rapidly. I've created a simple VI and placed the DAQ Assistant in a While loop that measures a 0-10V input voltage via my 6024E-DAQCard. The VI uses a global channel named MyVoltage that I've created. I've set the Analog Input Voltage Task to Acquire Continuously, 100 samples to read, at 1000Hz Rate. First, I have some questions about that. What does reading 100 samples at 1000Hz continously actually mean? How does this behave in a While loop? Am I making 100 voltagle measurements every time around the While loop? How does the rate work into this? Anyway, for testing, my VI currently just writes to a single digital line if the input voltage rises above some constant value, say 7 volts. This is working. But what I really need to do is set this same digital line if the voltage rises too quickly, like more than 1 volt per second. How would I accomplish this? Jeff
Re: Determining Voltage Rate of Change
The number of samples is irrelivent. The delta-T is derived from the sampling rate. In this case, 1000 HZ sample rate corresponds to 1 ms. delta-T. Good luck. Dave
Re: Determining Voltage Rate of Change
Take a look in the Functions/analyze/signal processing/time domain and select the Derivative x(t).vi. This should do the trick for you. Good luck. Dave
