Your PLC system doesn’t have to be a money-eating machine! With regular maintenance, you can keep your PLC and all its components running great for years without problems. Maintenance is one of the biggest things you can do not only to prevent problems with your PLC, but also to extend its life as well as the life of all its parts.
Avoid costly repairs and purchasing new parts or even an entire new system with these four PLC maintenance tasks that will keep your machine in optimal shape!
Check Analog Input Devices
When doing a regular maintenance check on your PLC, ensure that your analog components are in good calibration. We recommend that you follow the manufacturer’s schedule when performing regular maintenance; however, this is one of the things to check when doing so. If your system has issues with analog input modules, you may not need to replace the entire module, but rather just the transmitter that’s attached to it. Many problems with PLCs are due to I/O modules—when your analog input device isn’t correctly communicating the voltage to the processor, problems arise. When inspecting analog input devices, you can check the voltage accuracy by changing it and verifying that the change has registered on your input module. You may need an external meter to do this.
Ensure That Your PLC Isn’t Damaged from Environmental Components
One of the reasons PLCs are highly valued and so versatile is that they work well in harsh conditions. However, your PLC isn’t totally immune to environmental hazards that could affect its performance. Consider that chemicals such as chlorine, hydrochloric acid, and other elements often used in different processes can act as corrosive agents to your PLC, not only impacting performance but eventually leading to system failure.
While it’s not always easy to know what’s impacting your PLC and its performance, it is easy to schedule regular maintenance checkups in order to prevent problems from happening. Check your components and their cabinets. Dust, debris, and corrosion may be evident. Black dust is never a good sign and should be further inspected to determine the cause. You can also use canned air to help clean dust, and be sure to check the cabinet’s seal if you regularly find dust in the PLC’s components.
Examine Connections and Cables
Many complex problems are actually the result of connections and cables that have simply come loose. By checking cables and connections during your regular maintenance routine, you can ensure everything is connected. In the event that a problem does arise, you’ll know everything is connected and therefore be able to locate the source of the actual problem. Be sure to check in cabinets and areas where heavy vibrations occur, as these can cause connections to loosen over time.
Account for Electromagnetic Interference (EMI)
Getting a PLC demands that you take certain factors into account during the installation, but many times, EMI interference is not one of them. If your PLC is in an environment with high voltages and currents, EMI can be a problem that will affect your PLC. This is because higher currents produce EMI, and these wires that carry the currents could be problematic depending on their location. How can you prevent this from happening?
An audit of your wiring system can identify potential EMI problems before they happen. A good time to perform this audit is when designing or updating your wiring diagrams. Got analog signals going haywire? Check for sources of EMI. Even the older contactors on output modules can be a source of EMI. When communications begin making no sense and your PLC components are in good standing, EMI could be an influential factor.
By scheduling regular inspections, you’re preventing problems before they happen, therefore saving your industry time, money, and effort. Perform these four PLC maintenance tasks during your routine checks, and always align them with your manufacturer’s recommendations. You’ll minimize downtime, eliminate the need for new parts, and keep your machine running great for years. Make these four basic tasks a habit during your PLC maintenance routine!