Raspberry Pi

vs.

PLC

Choosing between Raspberry Pi and PLC (Programmable Logic Controllers) for industrial automation depends on your specific needs and priorities.

Here's a breakdown:

Strengths

  • Affordability: Significantly less expensive than PLCs, ideal for higher volume OEM products. 

  • Customization: A dedicated daughter board designed for your application moves complicated wiring to a printed circuit board, reducing cabinet built, installation, and diagnostic time.

  • A form factor to fit your machine. PLCs can be bulky and are meant for a control cabinet. For most of the machine builders, space is at a premium. A custom control system with Raspberry Pi at its heart can fit in the space you have.

  • Better remote support options: With access to the operating system, remote updates and diagnostics become significantly easier.

  • Flexibility: Having full control over the Linux OS and a diverse software ecosystem offers greater flexibility for custom programming and integration

  • Connectivity: Built-in Wi-Fi, Bluetooth, and Ethernet simplify data transfer and cloud integration.

Weaknesses

  • No guardrails. Many mistakes could doom a Raspberry Pi project. Everyone has heard of the problems with SD cards and other common complaints. You have to understand the engineering to make these projects shine. 

  • Perception. Customers have to be educated about the benefits of a Raspberry Pi-based solution. It's not as easy as referencing a Big 5 brand name.

PLC

Strengths

  • Pre-packaged solution. PLC manufacturers spend significant time and resources creating the best one-size-fits-most solution they can and then back it up with tech support and detailed manuals.

  • Perception. If you choose a PLC from a top 5 manufacturer, you can share in the reputation that the company has developed.

Weaknesses

  • Helplessness. Flaws in the operating system or firmware must be corrected by the manufacturer. The PLC manufacturer’s priorities for these repairs may not match yours.

  • Lifecycle. An OEM becomes dependent on the PLC manufacturer to continue supporting the product they have chosen. Decisions made in times of component shortages or life cycle reviews may not match your best interests.

  • Cost: More expensive than Raspberry Pi.

  • Limited flexibility: There are limited choices for IO configurations and form factors.

When to Choose Raspberry Pi

  • Higher volumes. Production of twenty (20) or more systems in a run will benefit from a Raspberry Pi solution with a bespoke daughter board. Lower volume systems are also practical with off-the-shelf industrial IO products as the interface.

  • You need a better user interface for your machine. With two (2) HDMI ports each capable of driving a 4K monitor at 3840 x 2160 pixels, the Raspberry Pi 4 can host two separate interfaces or one huge space up to 7,680 x 2160 pixels! This puts to shame a 12.1” Panelview with only 1280 x 800 pixels. With the wide variety of stock LCD touchscreens with HDMI interfaces available, you have more choices than ever before.

When to Choose PLC

  • The end customer requires it. Many large plants will require a certain make and model of PLC and they will accept nothing else. However, in many cases, the Raspberry Pi systems we offer run the same programming environment that the end user specifies. Most projects we offer are done in an IEC 61331-3-compliant environment that is compatible with PLCs offered by Schneider Electric, Eaton, Beckhoff, Bosch, IFM Efector, and Wago, among others.

  • You need to support an in-house programmer who only knows a certain brand of PLC.

Ultimately, the choice depends on your specific needs and priorities. Consider factors like complexity, budget, real-time requirements, safety, and environmental conditions.