Programmable logic controllers (PLC) have traditionally been hardware-based. They were as much a part of production lines as any other piece of physical equipment when they were born out of the car industry in the late 1960s.

Recently, software-based PLCs have appeared, asking the question: which is better positioned to support the future of manufacturing, a hard PLC or a soft PLC?

What exactly is a programmable logic controller (PLC)?

A programmable logic controller (PLC) is a computer or software that is specifically built to control various manufacturing processes such as assembly lines, production robots, automated equipment, and more.

They are often purpose-built and designed to handle industrial environmental conditions such as prolonged temperature ranges, high levels of electrical noise, and resistance to impacts and vibration.

How Are PLCs Programmed?

This is a question that is frequently posed. PLCs have significantly streamlined the job compared to the traditional use of electric relays.

●      Ladder logic is a common programming method for PLCs. Initially, ladder logic was created as a way to record the layout of electrical relay racks, which are wired in specific ways.

●      It served as the foundation for a programming language that accurately modeled the operation of electrical relays in real-world machinery like PLCs. It has a variety of advantages because it is a computing language that so closely mirrors the internal workings of these devices.

●      By requiring less technical knowledge, it makes it easier for maintenance engineers to troubleshoot problems. For instance, engineers don't need to comprehend the complexities of specialized programming languages.

Difference between a soft PLC and a hard PLC

A soft PLC motion control is defined as software that can perform the tasks of a PLC's CPU component while coexisting on hardware with other software.

A hard PLC motion control is a particular piece of hardware that only serves as a PLC, with its CPU activities taking place on a separate unit.

Since PLCs exist in so many different shapes and sizes, defining either kind by its inputs (sensors) or outputs (actuators) would rapidly become complicated. Instead, concentrate on where the CPU is located. So, a PLC is considered hard if a CPU is present in it. If it is present on a different computer, it is a soft PLC.

Why Are Soft PLCs Getting More Popular?

As we enter the era of Industry 4.0, we recognize that flexibility is a critical component of progress. Machine interoperability calls for ideas like soft PLCs, in which each manufacturing operation's possible setups are indefinitely flexible.

Future factories may have cloud-based CPU functionality that enables the simultaneous operation of several manufacturing facilities. That effectively places the PLC's accountability in the realms of IT, AI, and cloud computing.

It's crucial to keep in mind that with soft PLCs, the CPUs exist independently of the rest of the PLC.