December 14, 2018

Drive multiple speed with different reference using PLC

Drive nultiple speed with different reference using PLC




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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)