I use a numeric control (pointer slide to regulate 4..20 mA) to a controll valve

[ing.abdi]

Is there any one who can assist me with ideas.

the problem is that i have to manually operate the control valve 

I use a numeric control (pointer slide to regulate 4..20 mA) to a controll valve

I want to build a VI that does this automaticaly for me, rather than me increasing the value from 4..20 mA with a numeric controll

[PJS]

Not sure what the issue is.  Why not just replace your numeric control with a slider? You say you want to set it manually, but then you said later that you want it automatic? 

On my end, I am doing something similiar, but I usually convert the 4-20mA with %, but I WANT the operator to manually control the system, so they just select the % they want, and I convert that to a current output at the desired setting.

[Broken_Arrow]

So, you're just Opening a valve slowly? Change the Control to an Indicator, and write to it pragmatically to ramp it up from 4 to 20mA. A "reset" button could reset it to 4mA.

edit: "pragmatically"! I love spell check!

Message Edited by Broken Arrow on 11-25-2009 09:37 AM

[Cory_K]

Do you want to manually change the voltage or have the program do it automatically.

You can just make a loop with a wait in it and add to the voltage each iteration until it reaches the maximum.

[Alain_S]

Not sure if the OP needs just a "ramp" or any other form of "(PID)-regulation" to control the valve.

So we need more information about what regulation is needed ... ...