Hi, im very new to labview and have a problem that i thought would be simple to solve but it seems its not.. for me at least. I have labview controlling a DAQ which intern controls a motor controller to turn the motor for a pump system I am working on. It is very important for me to have very accurate control over the flow rate, and to do this testing I have been toggling the motor on and off at a certain voltage which corresponds to a specific flow rate. My problem is that I have been using a stop watch to measure the time the pump is on. I would would like to use labview to control this function. So all I need is this
Switch -> turns pump on and starts timer -> once time has elapsed (elapsed time should be changeable for differrent testing) motor is turned off.
Its very simple but Ive only picked up Labview a day ago and cannot figure out how to do it. Interfacing with my DAQ to control pump speed and monitor pressure and temp has been very easy with labview though. So far it has been pretty user friendly and well thought out. I would think that there has to be a simple timer somewhere.
Under the timing pallete, there is a vi called "Elapsed Time" that will work great for your problem. You can wire a control to the target time and the output can tell the motor to turn off or not. I like to use this in a state machine structure.
A good example that I have found that uses this type architecture is the Sample CLD Car Wash example.
This was made before the elapsed timer express vi was included with labview, but it gives you the same functionality and shows you how to do the countdown and check other things.