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Siemens SIMATIC controllers

Passion for Automation

Discover the exciting world of Programable Logic controllers

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Comparing PLC Brands

Which is the best PLC brand?

So many brands to choose from


Siemens Programmable Logic Controller

There are many PLC brands competing worldwide. Mostly PLC's dominate their home market with a lesser presence all over the globe. Siemens is a European PLC brand and have a solid foundation in Europe with support for many different languages. Allen Bradley is an American manufactured PLC with a solid foundation in the United States. Mitsubishi is an Asian manufactured PLC and dominates in the Asian markets.

List of PLC brands by popularity

  • Siemens Simatic PLC's
  • Rockwell Automation Allen Bradley PLCs
  • Schneider Electric Modicon PLCs
  • Mitsubishi Electric Melsec PLCs
  • Omron Sysmac PLCs
  • ABB AC500 PLCs


Considerations for choosing a PLC brand


Making a choice between PLC brands is not easy.A comparison of PLC brands will show that all are capable. When adding a new PLC to an exisiting installation, the choice is normally dictated by choosing brands that are already installed in the facility or shipped with the equipment that is used in the facility. This reduces the amount of critical spares needed, less skills required by personell and interchangeability of parts.

For new installations, the PLC is often aligned with the equipment beig controlled. For example, if the plant equipment is predominantly manufacturedin Europe, then it will most likely contain a Siemens PLC and Siemens should be considered. Alos, any special requirements should be taken into account. Profibus is a Euopean bus standard and is supported as standard on some of the Siemens CPU's. Foundation fieldbus is an American standard and not supported as standard on European PLCs.

The following should be considered when buying a PLC

  • Equipment being controlled, eg if switchgear is being controlled and the switchgear is manufactured by Siemens, then a Siemens PLC would be the best brand choice.
  • Geographic location. Support is always best in the region of manufacture. Poor manuals and documentation resulting from poor language translation is also an issue for some brands.
  • Reliability. Of course reliability is at the top of the list. But there are many reliable brands. Do not choose a brand that has no reputation
  • Support. Support is a critical factor when using PLCs. I you need an additional license because you projet has grown, or you need additional input and ouptut modules, strong vendor support is needed

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