Problems Working with PLC

Control panels are an essential part of the industrial automation. These control panels help in controlling different machines to perform different tasks that eventually combine to create an efficient work process. One of the most common types of controller used in such automation is the Programmable Logic Controller (PLC). Programmable Logic Controllers are computers that are programmed to control the different processes and function within an industry. A PLC can be used to control a single process or multiple processes.

Since a PLC controller is a machine at the end of the day, there are problems that can be faced when using it. Here are some of the common problems you may come across.


External factors can have a huge impact on any equipment including a PLC. As the PLC is constantly performing its task, lack of adequate ventilation can cause overheating in the PLC system. When planning a PLC structure for your industrial unit, it is essential to add air filters in the structure that keeps the air flow in the structure constant and keeps the PLC cool. The lack of proper air filtration causes the components within the PLC controller to fail. The buildup of humidity within the system can also lead to this failure.

I/O Module and Field Device Error

Sometimes the problems faced while working with a PLC can be due to factors that are not caused within the PLC system. The other components of the control panel may not sync with the PLC and cause trouble. Mostly this problem is faced due to the issue with the I/O module or the field device. A PLC controller is a computer, and it waits for a signal from the other components before it carries forwards a command. Sometimes these signals fail to pass at the field devices which causes the PLC to stop initiating the commands. Such an error can be identified with the help of an online software that traces the root cause of the problem. If an I/O error is identified, it could be anything related to a loose terminal block, wiring issue, failure of supply or configuration error. Field device error could be caused due to mechanical damage, water ingress, etc.

Grounding Error

Grounding is a factor that not only affects your PLC device but your overall equipment. If the structure of your equipment lacks proper grounding enclosure, your equipment can receive disturbance from external electrical noise. This can cause current fluctuations and lead to PLC dysfunction. For the identification of this error, an engineer can use a multimeter. Timely maintenance can also help the engineer to identify this problem through a visual check.

Internal PLC Error

Sometimes the PLC controller itself may experience failures within the system and result in major errors. These failures include erratic machine behavior or the complete breakdown of the controller. This will affect the overall integrity of the PLC controller which means that the PLC will not function electronically. To identify this error, you need a complete examination of the PLC controller along with the assessment of the ground wiring and power supply. Examining the ground wiring is necessary as it will let the engineer know about the loose connections, corrosion and other damages if any to the wiring. Checking the power supply is necessary to determine the voltage.

Electromagnetic Interference

A control panel has different parts, which work on different electrical charge. This is one of the reasons why it can face problems due to electromagnetic interference or radio frequency interference. These interferences can be caused due to haphazard welding in close proximity of the PLC controller, thunder striking due to weather change or simply due to hand-held radio transmitters. The radio waves and electrical charge passing through these factors interfere with the open electrical devices and disrupt the flow of work. In order to avoid such electromagnetic interference, the engineers need to add extra grounding and electrical insulation to the PLC controller.

Power Supply Error

For any equipment to function smoothly, uninterrupted power supply is a must. For this very reason, large manufacturing units always have a backup power supplying source to keep their processes nonstop. However, sometimes the PLC can experience a lack of proper power supply due to a sudden change in the source or due to corrosion in the power supplying wire. This results in the commands of the PLC being delayed or stopped, causing a problem. It may even lead to the PLC losing its memory, which will then need complete reprogramming by the engineer. To avoid this, large units should always keep Uninterruptable Power Supplies (UPS) ready.

Networking Error

The PLC controller performs the task of signalling different commands to different equipment parts such as machine interfaces and peripherals, to collaboratively perform a task. For this purpose, the PLC needs to have a constant network connection. If for some reason this network connection is lost, the smooth signal passage between these peripherals will be lost and the process will stop abruptly. Such a sudden pause will have a direct impact on the quality of the process. To avoid such a problem, engineers need to constantly check the connection between the different parts of the equipment and the PLC.

A PLC controller is a piece of efficient equipment that does an effective job of connecting the different parts of a control panel together and perform a task. Problems do persist but every problem has a solution, and all of the above-mentioned problems can be managed with the help of proper guidance. So if you want to go ahead with a PLC system, contact our engineers to have an error-free installation and systemized inspection.

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