Maintaining Old PLC Systems Without Expensive Upgrades

2025-09-12

How to know when to pay attention to the PLC module

The following are some abnormal phenomena that may occur during the use of PLC modules. When these phenomena occur, attention needs to be paid to the PLC module:

1. Temperature abnormalities: The PLC module should typically operate within a temperature range of 0-55°C. If the module's temperature is too high or too low, it may lead to damage to internal components or a decline in performance.

2. Humidity abnormalities: The relative humidity should be maintained between 35%-85%. If the humidity is too high or too low, it may cause damage to the internal components of the module or a decline in performance.

3. Dust and dirt accumulation: The printed circuit board and connectors of the PLC module are prone to the effects of dust, dirt, and debris, which could lead to poor contact or short circuits.

4. Electromagnetic interference: PLC modules are sensitive to electromagnetic interference (EMI), which can affect their normal operation. If there are strong electromagnetic sources nearby, it may lead to abnormal operation of the module.

5. Unstable power supply: Ensure that the power supply to the PLC module is stable and reliable, avoiding fluctuations or voltages that are too high or too low. An unstable power supply can lead to abnormal operation of the module.6. Program loss or damage: Regularly back up the programs and data in the PLC module to prevent any incidents of program loss or damage.7. Hardware component damage: Regularly check the hardware components of the PLC module, such as the printed circuit board, connectors, indicator lights, etc., for any damage, looseness, or corrosion.

Why is PLC used more in industry rather than microcontrollers? 

This is simply because from a technical perspective, there is no comparability between the two. A microcontroller is an integrated circuit system, while a PLC is a product developed based on microcontrollers, primarily designed for industrial field control environments.From the perspective of industrial field control environments, PLCs offer greater versatility and reliability compared to microcontrollers. They simplify design complexity, shorten development cycles, reduce the difficulty of troubleshooting, and enhance maintainability.Although considering costs, PLCs are priced higher, they require lower skill levels from operators. Typically, someone with a basic understanding of electrical knowledge can easily get started with PLCs, which helps the factory technical personnel to quickly solve problems. In contrast, microcontrollers require more from operators; without a computer foundation or knowledge of C language, it's difficult for beginners to start, as it involves many knowledge points and requires a long time investment to learn effectively.Moreover, PLCs are integrated systems based on microcontrollers in the industrial field, offering superior reliability, safety, and stability compared to microcontrollers, thereby becoming a specific product. If operators do not download control programs to the PLC, it serves no purpose and is just an ornament.PLCs are not just widely used in industrial settings; they are products that are specifically developed as a common platform for industrial environments.

Conclusion:

Strategic Approach to Long-term Development of Legacy PLCsFocus on Specific Industries: Cultivate industry users by building a good reputation and user base within a particular industry, gradually expanding market share.Regional Promotion Strategy: Start promotion in one or two provinces and then gradually expand. This approach helps companies concentrate their resources and achieve success in local markets before expanding nationwide.Increase Industry Promotion: Enhance brand awareness and user recognition, especially targeting industries with lower reliability requirements.Software Development and Upgrades: Increase efforts in software development to meet the demands of complex control and improve overall product performance.