Derivative Object

[Mike@DTSI]

I am trying to get the rate of change over 1 hour (in feet).

I have tried the derivative object all day. The input signal set to the input and the update on every update (using a pot and button for testing) have time set to 01:00:00

but i only works when it is polled 2 or 3 times

Any examples anyone has?

Thanks
Mike

[Carl_Finley]

Mike,
I have created a sample derivitive process I will attatch. It seems to be working fine for me. I have a simple pulse timer tripping every 5 seconds and a counter counting the timer trips. Obviously this will be a rate of rise of 12 per minute. I have a second counter that trips every 4 times the timer trips. This is updating my derrivative. I have been getting a derrivative of between 11.99 to 12.01.

One thing to remember is that it MUST update twice before you have the required information to calculate a derrivative. If you are still having problems, try a different update trigger, the duration on what you are using may not be long enough to execute properly every time.