By Eileen Harvey
Industrial communication networks are the backbone of modern factories and process industries, playing a crucial role in their operation and functionality. From automotive manufacturing plants to sophisticated chemical facilities and advanced robotics labs, the choice of network cable can significantly influence the efficiency and effectiveness of machine communication. A well-designed network ensures that data travels reliably and swiftly, which is paramount in environments where real-time monitoring and control are vital.
The longevity and durability of the infrastructure are also crucial factors, as these networks must endure the rigors of demanding industrial environments. Therefore, selecting the right communication protocol is not merely a technical decision; it is a strategic choice that can impact overall productivity and operational costs over time.
What is PROFIBUS?
PROFIBUS (Process Field Bus) is a mature field bus standard introduced in the late 1980s. It primarily enables communication between automation controllers and field devices like sensors, valves and drives. Known for its robustness and reliability, it is commonly used in manufacturing and process automation.
PROFIBUS uses serial communication based on RS-485 physical layer. It supports data rates up to 12 Mbps and is suitable for line or bus topologies. It is ideal for environments requiring deterministic communication.
What is PROFINET?
PROFINET (Process Field Network) is an Ethernet-based communication protocol developed by PROFIBUS & PROFINET International (PI). It’s designed for high-speed, real-time data exchange in modern industrial networks, supporting complex automation tasks.
PROFINET is based on standard Ethernet technology and supports data rates from 100 Mbps to gigabit speeds. Its flexible network topologies are star, line, ring or tree. And it is suitable for high-performance automation, robotics and motion control.
Cables Needed for PROFIBUS
Since PROFIBUS relies on differential serial signaling, the cabling must be designed to minimize electromagnetic interference (EMI) and maintain signal integrity. Typical PROFIBUS cable specifications are twisted-pair shielded (STP) or unshielded twisted pair (UTP), with impedance of 100 to 120 ohms. Shielding is recommended for industrial environments with high EMI. Ideal lengths are up to 1,200 meters at lower baud rates. Connectors should be M12, M8 or with screw terminals.
Use PROFIBUS-certified cables to ensure compatibility, to properly ground shields to reduce noise and to maintain proper cable routing to avoid interference.
Cables Needed for PROFINET
PROFINET utilizes standard Ethernet cabling, making use of commercially available network cables. Proper selection ensures high-speed, reliable communication, especially in harsh industrial environments.
Typical PROFINET cable specifications are Cat5e, Cat6 or higher (preferably shielded for industrial use). For shielding, shielded twisted pair (STP or S/FTP) is recommended in noisy environments. Recommended connectors are RJ45 Ethernet conforming to industrial standards. Length should be up to 100 meters per segment; longer distances require switches or repeaters.
PROFINET best practices: use industrial-grade Ethernet cables designed for harsh environments; ensure proper grounding and shielding; and use switches designed for industrial networks to extend or segment networks.
Which Cable Should You Choose?
Use PROFIBUS cables: for legacy systems or serial communication applications; in environments with minimal EMI; when cost-effective, reliable serial communication suffices; and for shorter cable runs within machinery or control cabinets.
Use PROFINET cables: for high-speed, high-bandwidth applications; in environments with high EMI where shielded Ethernet cables are necessary; for flexible, scalable network topologies; and when integrating with modern Ethernet-based devices and when future-proofing your system.
Installation Tips for Reliable Communication
- Proper shielding: Use shielded cables and ensure shields are grounded correctly.
- Cable routing: Keep communication cables away from power lines and sources of interference.
- Connectors and terminations: Use industrial-grade connectors and ensure secure terminations.
- Segmentation: Design the network to minimize segment length and avoid unnecessary loops.
- Environmental considerations: Select cables rated for the temperature, chemical exposure and mechanical stresses of your environment.
Recommendations
We recommend that you stick with PROFIBUS if you run a large-scale, legacy process plant where stability is key. Opt for PROFINET if you’re building or upgrading to a smart factory with robotics, automation and real-time communication. Thirdly, use hybrid strategies by using PROFINET for high-speed operations and PROFIBUS for existing equipment, and connecting them via gateways.
FAQs (Frequently Asked Questions)
Q1: Can I use PROFIBUS and PROFINET in the same network?
A: Yes, with gateways and converters, you can integrate PROFIBUS devices into PROFINET networks.
Q2: Is PROFINET always better than PROFIBUS?
A: Not always. While faster, PROFINET requires Ethernet infrastructure. PROFIBUS may still be better for simple, stable and cost-sensitive systems.
Q3: What’s the lifespan of industrial bus cables?
A: High-quality industrial cables like TKD Kabel can last 10 to 20 years, even in harsh conditions.
Q4: Do I need shielded cables for both?
A: Yes. Both PROFIBUS and PROFINET rely on shielding to protect against EMI in industrial environments.
Both PROFIBUS and PROFINET cables play crucial roles, but they serve different purposes tailored to specific applications. PROFIBUS, which stands for Process Field Bus, has established itself as a dependable choice, particularly in legacy process industries that have long relied on its robust architecture. These environments, often characterized by their need for stability and consistency, benefit from PROFIBUS's ability to maintain reliable communication over longer distances and in complex network configurations.
When choosing, consider your infrastructure, environment and future goals. For durable, high-performance solutions, TKD Kabel industrial-grade cables are trusted worldwide for reliability in even the harshest conditions.
About L-com
Explore the full range of TKD Kabel through L-com. We’ll fill your orders fast, with same-day shipping on all qualified, in stock, online orders received Monday through Friday before 5 p.m. EST. For TKD-related inquiries, connect with our U.S-based TKD expert Eileen Harvey at eharvey@infiniteelectronics.com.
