Why Some PLC Use Only the Basic Additions

Programmable Logic Controllers (PLCs) are widely used in industrial automation systems, and PLC programmers face various challenges. One of the critical programming considerations is the use of different operators, including arithmetic, logical, and comparison. This article explores why some PLCs use only basic additions and why this could be the optimal solution.

1. Simplification of Programming

One of the critical benefits of using only basic addition is that it simplifies the programming process. PLC programmers only need to create programs that use one or two operators, such as addition, subtraction, or multiplication. Such programs are easy to write, debug, and maintain, saving time and reducing errors in programming. It also reduces the likelihood of human error, which can cause significant problems in industrial control systems.

 

2. Speed and Efficiency

In some industrial control systems, speed is of the essence. Therefore, a basic addition operation can be faster to execute than other more complex operations. For instance, most PLCs have hardware capabilities for basic mathematical functions, including scaling, addition, and subtraction, but for more complicated operations, a more powerful CPU may become necessary. The use of basic addition, therefore, results in faster processing times and improved efficiency in the automation process.

 

3. Error Minimization

Using basic additions can help reduce errors in program execution. Complex and sophisticated mathematical operations can cause errors that are difficult to detect and correct. A simpler addition operator is easier to troubleshoot and debug, ensuring that errors don't propagate to other parts of the control system. This reduces the chances of system shutdowns and minimizes downtime.

 

4. Compatibility with Legacy Systems

One of the significant reasons for using only basic addition operators is for compatibility with legacy systems. Some industrial control systems are old, and the equipment they use may be outdated, or programming standards may have changed over time. The use of more sophisticated mathematical operators may require upgrading existing equipment, which may not be feasible. Using basic addition, therefore, offers backward compatibility to older systems and ensures seamless integration of system components.

 

5. Cost Implications

The use of more complex mathematical operators requires more advanced technologies, such as more powerful CPUs or dedicated modules for the processing of specific instructions. This may result in additional costs for equipment upgrades or additional modules. Using basic addition may allow the use of less expensive devices or keep the system within the existing hardware specifications.

Conclusion

In summary, the use of only basic addition in PLC programming is gaining popularity in industrial control systems. It offers numerous benefits, including simplifying programming, reducing errors, improving speed and efficiency, and offering backward compatibility to older systems. While more advanced mathematical operations are necessary for more complex automation systems, using basic math operations suitable for some industrial control systems has proven effective and efficient. Therefore, the decision on the use of mathematical operators mainly depends on the specific requirements of the control system and should be made carefully with these considerations in mind.