Automatic door system

Automaic door system.

Automatic door open close system.Learn how to write PLC program for automatic door open and close system.

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Controlling of conveyors with interlock

PLC Program: Conveyor Sequence Control and Interlocking

Problem Description

A feeder drops material onto Conveyor 1, which then transfers the material to Conveyor 2 for further processing. The system must function automatically—conveyors should start based on material detection using load cells. The system must ensure sequence control and interlocking to avoid collisions.

System Components and Setup

• PLC Type: Siemens S7-300

• Software: TIA Portal

• Material Detection: Load Cells (preferred over proximity or limit switches for higher reliability)

I/O List

Inputs

Address	Description
I0.0	START Push Button
I0.1	STOP Push Button
I0.2	Load Cell 1 (Conveyor 1)
I0.3	Load Cell 2 (Conveyor 2)

Outputs

Address	Description
Q0.0	Cycle ON Indicator
Q0.1	Conveyor 1 Motor
Q0.2	Conveyor 2 Motor
Q0.3	Feeder Motor

Ladder Logic Program Description

Network 1: System Start Logic

• When START (I0.0) is pressed and system is not in STOP mode (I0.1 not active), Cycle ON (Q0.0) is latched to keep the system running.

• This also starts the Feeder Motor (Q0.3) to begin dropping material.

Network 2: Conveyor 1 Activation

• If Cycle ON (Q0.0) is active and Load Cell 1 (I0.2) detects material, then Conveyor 1 Motor (Q0.1) turns ON.

Network 3: Conveyor 2 Activation

• When Load Cell 2 (I0.3) detects material (i.e., material has transferred from Conveyor 1 to Conveyor 2), then Conveyor 2 Motor (Q0.2) turns ON.

Network 4: Emergency Stop Logic

• If STOP Button (I0.1) is pressed, all outputs are turned OFF by resetting the Cycle ON (Q0.0) latch.

Functional Sequence (Interlocking Logic)

1. START Button Pressed (I0.0 = 1):

   • Q0.0 (Cycle ON) = 1

   • Q0.3 (Feeder Motor) = 1

2. Material Detected on Conveyor 1 (I0.2 = 1):

   • Q0.1 (Conveyor 1 Motor) = 1

3. Material Transferred to Conveyor 2 (I0.3 = 1):

   • Q0.2 (Conveyor 2 Motor) = 1

4. STOP Button Pressed (I0.1 = 1):

   • All outputs reset (Q0.0–Q0.3 = 0)

Runtime Test Cases

Inputs	Outputs	Physical Behavior
I0.0 = 1	Q0.0 = 1	Cycle ON Lamp turns ON
I0.2 = 1	Q0.1 = 1	Conveyor 1 Motor starts
I0.3 = 1	Q0.2 = 1	Conveyor 2 Motor starts
I0.1 = 1	All Q outputs = 0	System stops

Conclusion

This PLC program ensures automatic sequencing and interlocking of conveyor belts using load cell feedback. It minimizes manual intervention, improves reliability, and provides a robust material handling solution using Siemens S7-300 and TIA Portal.

Would you like me to also draw the ladder diagram or generate an image of the conveyor setup for better

 

First scan cycle

First scan cycle .

This is PLC Program for the first scan cycle.

Problem Description:-

Problem Diagram

Problem Solution

Program

Here is PLC program the first scan cycle.

List of inputs/outputs

Inputs List:-

Outputs List:-

Ladder diagram for the first scan cycle.

  



FBD diagram for the first scan cycle.

Program Description