control sytem

[santoshbehera]

Dear all

           I want to devlop control system for creating pulsation of water in a u tube.one side of u tube is connetecd air compressor through valve .one side of u tube filled with air  i.e connected to compressor throgh valve and another side with water and level sensor is here to measure mimimum and maximum levle of water.water and air is separeted by mesh.i would like to oscillate this water by opening and closing the valve by measuring minimum and maximum level of water(level is our feedback signal).i also like to maintain pressure of compressor.i am having labview8.5.1 academic version as well as ni cdaq-9172 and analog input output module.i am not having experience on cotrol system using ni.i would like to know which ni hardware will use for this appliaction.here i  want to control loop ,one is to maintain pressure of compressor and is to create oscialtion by controling valve .i have attached schmatic diagram of my ystem.plz hepl me.

with regards

santosh

santosh_behera_78@yahoo.com

[Ben]

I would like to suggest you start by looking through the Examples that ship with LV that allow continuous data acquisition since the first step in controlling a system is measuring it.

The next logical step would be to do the same to understand the capabilities of your hardware output channels.

NI SImulation and Control tools include a PID toolkit that you probably use out of the box for both of values you want to control. WHen you have then under control and tuned in steady-state then you introduce the required modulation of the set-point to get the oscillation you are after.

But start out simple to make sure you understand the tools you have before you dive into trying to control a reactor.

WARNING!

Make sure you have adiquit manual saefty over-rides in place in the event your app decides it want to update its virus protection at a bad time.

Ben