PLC LCD Display: Connect LCD Module in One Day for Clear Parameter Display

Want to quickly implement LCD display with PLC and make parameter presentation clear at a glance? This guide teaches you how to connect the LCD module to the PLC in just one day through simple steps, achieving intuitive and clear parameter display.

5 Major Challenges in PLC LCD Display

Complex connection wiring, hard to start

Complicated parameter configuration, prone to errors

Poor display quality, not clear enough

Data updates are not timely, with significant lag

Difficult integration with PLC programs

🎯 Core Solution: Reasonable Wiring + Precise Configuration

Tools Required:

✅ PLC controller (supports LCD display expansion)

✅ LCD module (compatible model with PLC)

✅ Connection cables (ensure quality)

✅ Programming software (corresponding to PLC model)

Four Steps to Connect

▎ Stage One: Hardware Connection (Complete in 30 Minutes)

Wiring Planning

Plan the connection wiring according to the PLC and LCD module manuals, ensuring the wiring is neat and orderly to avoid cross-interference.

Connect the power lines, ensuring the PLC and LCD module are powered correctly, paying attention to the correct connection of positive and negative terminals.

Port Matching

Connect the data line of the LCD module to the corresponding data port of the PLC, paying attention to the interface type and pin definitions.

Connect control signal lines, such as RS232, RS485, etc., selecting the appropriate communication method based on actual needs.

Fixed Installation

Secure the PLC and LCD module in a suitable position to avoid vibrations and displacements affecting connection stability.

▎ Stage Two: Parameter Configuration

Communication Parameter Settings

Open the programming software and enter the PLC communication parameter settings interface.

Set the baud rate, data bits, stop bits, and other parameters for communication with the LCD module, ensuring they match.

Display Parameter Adjustments

Configure the number of display rows, columns, font size, and other parameters of the LCD module based on actual display needs.

Set the refresh frequency of the display content to ensure timely data updates.

Pitfall Avoidance Tips:

Carefully check communication parameters to avoid communication failures due to incorrect parameters.

When adjusting display parameters, observe the display effect and make timely adjustments.

▎ Stage Three: Program Integration (Key Step)

Data Reading and Transmission

Write data reading code in the PLC program to read the parameters to be displayed from sensors or other devices.

Transmit the data to the LCD module via the communication protocol, ensuring data accuracy.

Display Logic Design

Design the display logic, such as displaying parameters in a certain order or using different colors based on parameter values.

Write programs to achieve dynamic displays, such as scrolling displays or flashing alerts.

Practical Tips:

Preprocess data, such as unit conversion and data filtering, to improve display accuracy and readability.

Write exception handling programs to provide timely alerts in case of data anomalies or communication failures.

▎ Stage Four: Display Optimization

Brightness and Contrast Adjustment

Adjust the brightness and contrast of the LCD module based on the usage environment to ensure clear visibility.

Automatic brightness adjustment can be implemented through the PLC program, adjusting display brightness based on changes in ambient light.

Color Matching Optimization

Select appropriate color combinations to make the displayed content more eye-catching and aesthetically pleasing.

For important parameters, use striking colors to draw the operator’s attention.

Multi-Scenario Parameter Library

|———|———|———|———|

| Bright Indoor Environment | 50% | 40% | Black background with white text |

| Dim Indoor Environment | 30% | 30% | Green background with white text |

| Outdoor Bright Light Environment | 80% | 50% | White background with black text |

Practical Case:

Industrial Automation Production Line Parameter Display:

Real-time display of equipment operating speed, temperature, pressure, and other parameters, with timely and accurate data updates.

When parameters exceed normal ranges, the display color changes to red and flashes to alert.

Smart Agriculture Greenhouse Environment Monitoring:

Display environmental parameters such as temperature, humidity, and light intensity inside the greenhouse.

Display different icons based on different parameter ranges, such as a flame icon for high temperatures.

Common Problem Rescue Tips

▎ Display Garbled?

Check if the communication parameters are correct and reset them.

Confirm if data transmission is correct, checking the data processing part in the PLC program.

▎ Display Incomplete?

Check the display parameter settings of the LCD module and adjust the number of display rows and columns.

Confirm if data is completely transmitted, checking the data reading and transmission program.

▎ Communication Interrupted?

Check if the connection cables are loose and reconnect them.

Check if the communication interfaces of the PLC and LCD module are damaged, replacing them promptly if damaged.

💻 Device Compatibility Solutions

|———|————|————|———|

Choose devices wisely based on project requirements to ensure stable and reliable operation of the PLC LCD display system.

—— End ——