Loop Iteration- Valve control

[Jmc006]

Hello, I am controlling a discharge air valve with a 4-20 mA signal.  The user manually positions the slider to close that valve to a certain point, and then I need to record that point(say 12 mA) and then open the valve slowly by .1 mA to about 13mA.  My major problem is the fact that the valve is controlled by the user(slider), and then needs to be controlled by the loop counting up by .1 mA at a time.  How do I do this?  I can write a loop that counts up by .1 mA at a time, but I cannot make it take over the job of the slider as a control.  I would like the user to click a button and than have the value recorded, and that valve the start opening up slowly.  Does anybody have any input?

Thanks..

[devchander]

This is one way to do it

Use event cases

create an event case for the value change of the slider and inside that event, you can keep a loop for incrementing the slider value in steps by employing a property node of that slider.

Plus you may also have to think of some logical checks/ condition checks if you want to prevent this incrementing loop inside event case from executing each time you change the slider value.

Hope this helps

regards

Dev

[johnsold]

Use the slider to control the setpoint, not the valve itself. When the setpoint changes (detected by an event structure as devchander suggested), change the valve control output in 0.1 steps from its current value to the setpoint value.

Lynn