Automatic Lamp Control

Automatic Lamp ON/OFF Control in a Godown using PLC

Problem Statement

In traditional setups, when someone enters the godown (storage area), they manually press a switch that turns all lamps ON simultaneously. This leads to unnecessary energy consumption, especially when only certain segments are in use.

A solution is needed to optimize power usage with segment-wise automation.

Diagram:-

Automated Solution Using PLC

We’ve implemented a simple automation system using a PLC (Siemens S7-1200) and the TIA Portal software.

The godown is divided into three segments, each with:

• One lamp
• One switch
• Interlocking logic to prevent multiple lights from running at once

Operation Logic:

• When the user presses Switch 1 (SW1) → Lamp 1 turns ON.
• The system locks control of Lamps 2 & 3 until Lamp 1 is turned OFF.
• This pattern is repeated for each segment, enforcing sequential access to lighting and conserving energy.

PLC I/O List

Digital Inputs	Digital Outputs
SW1 = I0.0	Lamp 1 = Q0.0
SW2 = I0.2	Lamp 2 = Q0.1
SW3 = I0.3	Lamp 3 = Q0.2

 

Ladder Logic Summary

• Network 1:

• Lamp 1 (Q0.0) is triggered via NO contact of SW1 (I0.0)
• NC contacts of other switches are used to ensure interlocking

• Network 2:

• Lamp 2 (Q0.1) uses NO contact of SW2 (I0.2)
• Interlocked via NCs from other segments

• Network 3:

• Lamp 3 (Q0.2) uses NO contact of SW3 (I0.3)
• Follows similar interlocking structure

Runtime Test Scenarios

Input Conditions	Output States	Lamp Status
I0.0 = 1	Q0.0 = 1	Lamp 1 ON (Lamp 2 & 3 OFF)
I0.2 = 1	Q0.1 = 1	Lamp 2 ON (Lamp 1 & 3 OFF)
I0.3 = 1	Q0.2 = 1	Lamp 3 ON (Lamp 1 & 2 OFF)