Talking about Process Control and PLC Tutorial

Programmable logic controllers (PLCs) can save time, money and energy in process control systems. They simplify the system. The short history of the manufacturing process laid the foundation for how to use modern ICs to replace discrete components. These ICs allow simple system design and expand the monitoring range to improve the safety of equipment and personnel. MAX15500/MAX15501, MAX5661 and MAX5134–MAX5139 are used as examples of process control ICs.

    Introduction

    Industrial control, factory automation and PLC (Programmable Control Logic) do well, they can save time, materials, energy and money. But where do we start? Building a complete automated factory is a huge job, and some people may give up before starting.

    We recalled that a few years ago explorers in Africa asked local tribe members: "How does an elephant eat?" The tribe members looked at this explorer in surprise and replied: "We are just like eating other things. One bite." Like most large systems, industrial control consists of many smaller circuits. We will explore some of these little "bites".

    Process control

    The assembly line is a relatively new invention in human history. There may have been many parallel inventions in many countries. In the brief history of the process that is about to become a fully automated factory, we will only mention some of them.

    American gun manufacturer Samuel Colt (Samuel Colt) demonstrated interchangeable parts in the mid-1800s. Previously, each gun was assembled with separately manufactured parts, which had to be suitable. Mr. Colt showed the fragments of ten guns, and then he assembled a gun by randomly grabbing the fragments from the trash can. At the beginning of the twentieth century, Henry Ford expanded mass production technology. He uses fixed assembly stations to move the car between positions. The employees only learned a few assembly tasks and performed them for several days in a row. In 1954, George Devol applied for 2,988,237 in the United States, which gave birth to an industrial robot called Unimate. By the late 1960s, General Motors used PLC (Programmable Logic Controller) to assemble automotive automatic transmissions. Dick Morley, known as the "father" of PLC, participated in the production of GM's PLC Modicon. His US 3,761,893 is the basis of many PLCs today.

    How simple is the process control? Figure 1 shows a common household space heater.

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    The components of the heater are enclosed in a container, making system communication easy. An extension of this concept may be a household forced air heater with a remote thermostat. The communication path is only a few meters, and voltage control is usually used.