# PLC Level Control of Two Tanks

## PLC Level Control of Two Tanks

This is PLC Program for Level Control of Two Tanks

## Problem Description

Two simultaneous process are to be performed in two separate tanks which are connected through a valve. First Process takes place in process tank 1 and second process takes place in tank 2. Write the ladder program for level controlling of two tanks in PLC.

### Problem Solution

• Arrange two pressure controlled tanks for processes. Process 1 will be done in process 1 tank and process 2 will be done in process 2 tank.
• Use an inlet vale for material inlet in process 1 tank. Add one more valve between two tanks as a connecting valve.
• Consider two sensors (High and Low) for process 1 tank and consider only low sensor for process 2 tank.
• For this application we can use PLC, we will write PLC program for this application.

### List of inputs/outputs

#### Digital Inputs

• Cycle START :- I0.0
• Cycle STOP :- I0.1
• Low level process 1 tank (LL1) :- I0.3
• Low level process 2 tank (LL2) :- I0.4
• High level process tank 1 (LH1) :- I0.5
• Process 1 done :- I1.0
• Process 2 done :- I1.1

#### Digital Outputs

• Inlet valve :- Q0.0
• Connecting valve :- Q0.1
• Outlet Valve :- Q0.2

#### M memory

• Cycle ON bit :- M0.0

### Program Description

For this application we used S7-300 PLC and TIA portal software for programming. We can implement this logic by using other PLC also.

#### Network 1 :-

Network 1 is for latching circuit. Whenever START button is pressed (I0.0), Cycle ON (M0.0) bit will be ON. Cycle can be STOP by pressing STOP PB (I0.1).

#### Network 2 :-

If LL1 (I0.2) is detected and cycle START is pressed, an inlet valve (Q0.0) will be ON. Consider LH 1(I0.3) interlock during this function.

#### Network 3 :-

When the level of material of process tank 1 goes high hence LH 1(I0.3) is detected and level of material in process 2 tank goes low, connecting valve (Q0.1) will be ON. This function takes place while PLC is detecting process 1 done command.

#### Network 4 :-

When process 2 is completed and process 2 tank is not low, an outlet valve (Q0.2) will be ON. Cycle ON bit (M0.0) should be ON during the whole cycle.

Note :- Above application may be different from actual application. This example is only for explanation purpose only. We can implement this logic in other PLC also.

### Runtime Test Cases

Author : Bhavesh

PLC Selective Execution of the Application

VFD Motor Speed Control

PLC Heating and Mixing of Products

Two Way Switch Logic using PLC

PLC Counting Moving Objects