Implementing PID control loop between flow meter and pump

[Vvk01]

I have to make a system.

In which flow out is given to pid and pid out is given to drive.

How to make such a system ?

I have to stop the drive after flow meter shows 200 liters 

Is this type of system possible? 

Can we swich on and off a drive using pid o/p

[GerdW]

Hi vvk,

How to make such a system ?

The same way as you described it: read the input, decide what to do, drive the outputs…

I have to stop the drive after flow meter shows 200 liters Is this type of system possible?

It's just an additional condition to your control loop.

Can we swich on and off a drive using pid o/p

Well, you could - but would it make sense?

Usually PIDs are used to drive analog outputs.

With digital outputs (on/off) I only use PIDs to generate PWM signals - you could count that as "on/off" too…

Please explain why you want to use a PID here. From your (minimalistic) description it seems to me you only need to switch on a pump, wait until you got 200l, then switch off the pump…