4 Factors to Consider When Choosing Which PLC Brand to Use in Your Studies

Fri, 10/30/2020 - 11:31

As we know there are several different brands of PLCs used in the industry today. So, you may be asking which PLC system should I study. Unfortunately, there is no simple answer to that question but there are several factors that can help you choose which PLC brand to learn and help you excel in your career as a technician.


PLCs have been around since 1968; however, as the world marches on into the fourth industrial revolution (also known as Industry 4.0), they continue to be the bedrock of industrial automation. Today, Allen Bradley (AB) and Siemens are two PLC giants and are widely used around the world. This blog will highlight how these two brands differ and what impact these differences can have when considering which brand of PLC would be best to use for your studies.

What Factors To Consider When Allen Bradley or Siemens?

The decision to study one PLC brand (AB or Siemens) rather than the other may be impacted by one or all of the following:

1. Location, Location, Location

Different PLC platforms are preferred in different parts of the world. Your job location becomes very important when making this determination. It might be better to choose from the popular PLC brands used in your geographic region. If you look at North America, Allen-Bradley has a market share of 50%-60% while Siemens have around 20%-30%. Students in North America prefer to study Allen Bradley PLC systems. Siemens PLCs are hands-down the most popular of the two in Europe (70%), where Siemens AG also happens to be the largest industrial manufacturing company on the continent

2. PLC Programming Knowledge

Allen Bradley comes with a more intuitive user-interface and does not require an extensive programming background.  If you are familiar with relay logic, you may find it easier to use an Allen Bradley system which provides the ability to program using ladder logic. On the other hand, Siemens PLCs can be heavily programmed and customized to suit a particular business need. Naturally, this implies that a more robust computer programming background will be needed in order for a technician to effectively make use of and maintain a Siemens PLC.

3. System Differences

Allen Bradley and Siemens PLCs work pretty much the same way and are equally reliable. One difference lies in their installation processes. While Allen Bradley requires you to connect the PLC to both the Allen Bradley power supply as well as the Allen Bradley rack, Siemens works with pretty much any 24 V DC supply. Also, you may need to install additional safety communication ports when working with AB, while Siemens already comes with built-in communication ports. Another major difference is in the protocols that they use. AB uses mostly native American IPs such as DeviceNet, ControlNet and EthernetIP, as well as DH+ or DH485. On the other hand, Siemens uses European native IPs such as Profibus and ASI as well as serial MODBUS or MODBUS TCP/IP.

4. PLC system used in your facility

If you work in a manufacturing facility, you should focus on learning the system that is already implemented within that facility. Make an effort to study the most current version of the appropriate vendors PLCs.  For instance, if your place of work uses AB 500 series controllers, you may want to study the AB 500 series of controllers. This will help you become a specialist within your organization, allowing you to and train others or even take on more responsibility.

Importance of Plc Programming Knowledge for A Beginner

Regardless of the system, each technician who interacts with a Programmable Logic Controller has to go through a series of lessons on PLC hardware, programming, troubleshooting, and design. All PLC manufacturers follow the IEC 61131-3 standard in terms of programming languages and it is always advantageous to learn a new one. In general, once you have mastered French or Spanish, it gets easier to learn another romantic language. Similarly, it is very important to learn the fundamentals of PLC programming rather than focusing on a specific brand of a PLC. Once you have mastered the logic behind a programming language used by one brand of PLC, you can easily apply your knowledge on any brand. Of course, given that a one-size-fits-all approach is rarely ideal, there’s no clear “winner” when comparing the two brands...

Learn more about factory automation using AB Rockwell PLCs by checking out George Brown’s PLC technician training programs. For more information, please reach out to us at 1-888-553-5333 and speak with one of our Program Consultants.


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