PROFIBUS vs. PROFINET: Path to the Future

What sets PROFIBUS apart from PROFINET? Let's delve into this intriguing question and compare these two communication technologies.

30.08.2023

By Egle Dambrauskaite

Distinguishing PROFIBUS from PROFINET

PROFIBUS, established in 1989, is a veteran serial Fieldbus, while PROFINET represents the industrial Ethernet protocol, a future-proof solution. Both standards emerge from the same organization, PROFIBUS and PROFINET International, yet their characteristics markedly differ.

History and future direction

Introduced in 1989, PROFIBUS rapidly expanded throughout the 1990s as a pioneer in fieldbus technology. However, the monumental shift towards industrial Ethernet took place around 2000. In response, PROFINET was developed to meet the new demands. Commencing in the early 2000s, PROFINET has consistently evolved to suit the needs of the modern industry.

Technical Disparities

PROFIBUS networks (based on RS-485) can achieve speeds up to 12 Mbit/s, though most operate at 1.5 Mbit/s. Telegram size can extend to 244 bytes, with an address space limited to 126 devices per network. PROFINET networks attain speeds of 100 Mbit/s or even 1 Gbit/s and beyond. Telegram size can reach 1440 bytes, and there are no restrictions on address space. While the specification doesn't limit address space, individual controllers will have limitations based on their processors and memory.

Transition from RS-485 to Ethernet signifies a move toward more advanced technology. Since PROFINET exclusively utilizes standard Ethernet, it's future-proof; as commercial Ethernet evolves, PROFINET can capitalize on these advancements. When PROFINET was introduced, 100 Mbit/s Ethernet was the standard. Presently, PROFINET operates seamlessly on today's Gigabit Ethernet (and higher). The shift to Ethernet-based technology allows for greater bandwidth, larger message sizes, and unlimited address space.

Data Transmission

Master/Slave to Provider/Consumer PROFIBUS employs a master/slave model, while PROFINET utilizes a provider/consumer scheme. In PROFINET, both controllers and devices are active consumers and providers of data. This flexibility is key to establishing efficient two-way communications.

Ports and Future Focus

Companies have devised gateways to translate to PROFIBUS from other networks. PROFINET has gone a step further by defining proxies in its own specification. Proxies resemble gateways in the sense that they translate one network to another, yet unlike gateways, they are defined by an open standard. PROFINET offers proxies for PROFIBUS DP, PROFIBUS PA, AS-i, IO-Link, DeviceNet, Foundation Fieldbus, CANopen, Modbus, HART, and more. For instance, IO-Link and AS-i proxies enable communication with smart devices lacking an Ethernet port. When to use one over the other? Brownfield - use PROFIBUS. Greenfield - use PROFINET. A brownfield site already equipped with PROFIBUS can continue adding PROFIBUS nodes. However, if you need to incorporate Ethernet functionality, considering a smaller PROFINET project could be worthwhile.

Applicability to Your Business

PROFIBUS and PROFINET boast distinct characteristics and benefits. The choice between them hinges on your facility's current status and future aspirations. Choosing between PROFIBUS and PROFINET relies on multiple factors, including your existing system, specific needs, and future goals. Here are some general guidelines for considering each technology:

PROFIBUS

Established systems (Brownfield): If your facility already operates with a functional PROFIBUS infrastructure and you don't require higher data rates or advanced features, continuing with PROFIBUS could make sense. It's cost-effective to add more nodes to existing PROFIBUS networks.
Less complex applications: If your application has simpler requirements, such as basic data transfer and fewer real-time performance demands, PROFIBUS might suffice. It's suitable for less complex industrial applications.
Budget constraints: If you have a limited budget and don't need the advanced features that PROFINET offers, PROFIBUS could be a more cost-effective alternative.

Future-oriented infrastructure (Greenfield): If you're constructing an entirely new facility or planning a significant upgrade, PROFINET is the more future-proof option. It provides higher data rates and supports more complex and demanding applications.
High data performance requirements: If your application necessitates faster and more reliable real-time data transfer, PROFINET is the superior choice. PROFINET can handle higher data rates and offers more advanced automation features.
Network design flexibility: If you require network design flexibility, including various topologies and the possibility of wireless connections, PROFINET is the better option. PROFINET provides more freedom to customize your network to specific needs.
Integration with other systems: If you need to connect to other modern IT systems and IoT platforms, PROFINET is advantageous, as it's based on Ethernet technology common in the IT world.

In conclusion, if you have an established PROFIBUS environment and simpler needs, PROFIBUS could be a suitable solution. If you're aiming for a modern and future-proof infrastructure with high performance requirements, complex applications, and the need for flexibility, PROFINET is the better choice.

A journey to the future begins here – the choice is yours! Contact us , and we'll explore how we can assist your business or delve into the product finder .

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