Innovative Applications: New Ways to Use Schneider PLC in Smart Homes for a Comfortable and Convenient Life

Innovative Applications: New Ways to Use Schneider PLC in Smart Homes for a Comfortable and Convenient Life

Hello everyone, I am Engineer Liu. Recently, while chatting with several long-time clients, I found that they are particularly interested in the application of PLCs in home scenarios. Today, let’s discuss how to use PLCs to achieve smart home control, making our lives smarter and more comfortable.

Why Choose PLC for Smart Homes?

When it comes to smart homes, there are many ready-made products on the market. However, using PLCs for smart home implementation has several unique advantages:

• Good stability, with industrial-grade product quality assurance
• High functional flexibility, allowing for custom solutions based on needs
• Strong anti-interference capability, unlike WiFi which can easily disconnect
• Easy maintenance, with straightforward problem localization and resolution

Basic Hardware Configuration

The core device selected is the Schneider M221 series PLC, with the following specific configuration:

• CPU: TM221CE16R (with Ethernet, 8 inputs and 8 outputs)
• Expansion Module: TM3AM6 (analog module for temperature acquisition)
• Touch Screen: HMIST6400 (7-inch color screen, installed on the kitchen wall)

Main Functionality Implementation

1. Smart Lighting Control

The living room lighting is divided into three zones, each of which can be controlled separately. The M221’s relay outputs directly drive the contactors of the lighting circuits, which can be controlled via the touch screen and mobile app.

Key Code:

oxygene copy

(*Zone Lighting Control*)
IF %M100 THEN  // Mobile app switch command
    %Q0.0 := TRUE;  // Main lighting in the living room
END_IF;

IF %M101 THEN
    %Q0.1 := TRUE;  // Dining room lighting
END_IF;

(*Automatic Lighting Mode*)
IF %I0.0 AND %MW50 < 100 THEN  // Human detection and low light
    %Q0.0 := TRUE;
    TMR0.IN := TRUE;  // Start delay
END_IF;

2. Temperature Control System

Using the analog module to collect indoor temperature, automatically controlling the air conditioning and underfloor heating based on set values.

oxygene copy

(*Temperature Control*)
temp_real := INT_TO_REAL(%IW0.0);  // Read temperature value
temp_act := (temp_real / 4095) * 100;  // Convert to actual temperature

IF temp_act < temp_set - 1.0 THEN
    %Q0.3 := TRUE;  // Turn on heating
ELSIF temp_act > temp_set + 1.0 THEN
    %Q0.3 := FALSE;  // Turn off heating
END_IF;

3. Smart Curtain Control

Automatically control the opening and closing of curtains based on time, light, and temperature, with the option to set fixed time periods for automatic control via the touch screen.

Practical Tips

1. Wiring Points: Keep weak current control signals and strong current wiring separate to avoid interference.
2. Debugging Experience: When debugging new functions, first use analog signals to replace actual loads for testing, such as using indicator lights instead of actual lighting.
3. Safety Protection:

• All strong current circuits must have leakage protection
• Curtain motors should have limit protection
• Key devices should be equipped with UPS backup power

Common Problem Solutions

1. Touch screen occasionally freezes

   Reason: Mostly due to communication quality issues

   Solution: Check cable connections, and install signal amplifiers if necessary

2. Temperature control is unstable

   Reason: Improper placement of temperature sensors

   Solution: Avoid placing near air conditioning vents, and choose appropriate installation locations

Expansion Application Suggestions

1. Add air quality sensors to link with fresh air systems
2. Integrate with access control systems to achieve automatic mode when leaving home
3. Combine with IoT modules for remote monitoring

Practical Exercise Suggestions:

1. Build a simple lighting control circuit using relays and buttons
2. Write a basic temperature acquisition and display program
3. Implement a simple timing control function

With the development of technology, PLCs will have more applications in the smart home field. Engineers with strong hands-on skills can completely create a personalized smart home system.