By Eileen Harvey
Conductors, the core of any cable, determine the efficiency of signal transmission, while shielding plays a critical role in minimizing electromagnetic interference that can degrade performance. Additionally, impedance is a crucial parameter that influences signal integrity and compatibility among connected devices. Whether in automotive systems, industrial automation or consumer electronics, the knowledge of bus cable anatomy is indispensable for ensuring optimal functionality and longevity in electronic communication networks.
Various protocols, such as PROFIBUS, CAN-Bus and AS-i Bus, play a crucial role in ensuring that data is transmitted effectively and efficiently across a range of devices and systems. Each of these bus cables is designed to withstand the challenges posed by harsh industrial environments, which often include extreme temperatures, electromagnetic interference and exposure to chemicals. Therefore, selecting the right bus cable becomes a critical decision for engineers, plant managers and technicians who aim to maintain seamless operations in their facilities.
What Are Bus Cables?
A bus cable is a specialized communication cable designed to connect devices in industrial networks. Unlike standard cables, bus cables are engineered for signal integrity over long distances, resistance to electromagnetic interference (EMI) and durability in harsh environments such as heat, oils, chemicals and vibrations. They are widely used in factory automation, including robotics, conveyors and PLCs; in process industries such as oil and gas, water treatment and pharmaceuticals; and in automotive and transportation applications.
Conductors in Bus Cables
At the heart of every bus cable is the conductor, which serves as the pathway for electrical signals.
Types of Conductor Materials
Bare copper offers excellent conductivity and is widely used. Tinned copper resists oxidation, making it ideal for humid or corrosive environments. Silver-plated copper is the premium option, often used in high-frequency or aerospace applications.
Stranded vs. Solid Conductors
Solid conductors are better suited for fixed installations. An example is the PROFIBUS DP Cable 22AWG Solid. Stranded conductors provide greater flexibility and can withstand bending and movement, making them a practical choice for dynamic environments. A common example is the CAN-Bus 24AWG Stranded Cable.
Conductor Size (AWG)
Thicker conductors, such as 18AWG or 20AWG, offer lower resistance and are better for long distances. Thinner conductors, such as 22AWG or 24AWG, are more flexible and suitable for shorter runs.
Shielding in Bus Cables
Bus cables often operate in electrically noisy environments, where motors, drives and welding machines can cause EMI (electromagnetic interference) that may lead to data loss. To prevent this, shielding is critical.
Types of Shielding
Foil shielding provides 100 percent coverage and is lightweight and cost-effective. Braided shielding is more durable and offers superior mechanical strength. A combination of foil and braid delivers the best of both worlds and is commonly used in industrial bus cables.
Impedance in Bus Cables
One of the most overlooked yet critical features of bus cables is impedance.
What Is Characteristic Impedance?
Impedance, measured in ohms, is an essential electrical characteristic that quantifies the resistance a cable provides to alternating current (AC) signals. Unlike direct current (DC), where resistance is relatively straightforward, AC introduces more complex interactions due to the frequency of the signal and the cable’s physical properties. Impedance therefore accounts not only for resistance but also for reactance, which arises from the cable’s inductance and capacitance. For engineers and technicians designing and implementing electrical systems, understanding impedance is vital, especially in applications where signal integrity is paramount.
Why Is It Important?
If impedance is mismatched, signals may reflect within the cable. This can cause data errors, reduced transmission speed and even network failures.
Jacket Materials in Bus Cables
The outer jacket of a bus cable protects its internal structure from mechanical, chemical and environmental stress.
Common Jacket Materials
PVC (polyvinyl chloride) is cost-effective and flame-retardant. An example is the PROFIBUS PVC Cable. PUR (polyurethane) is flexible and abrasion-resistant, making it ideal for robotics and moving machinery. TPE (thermoplastic elastomer) provides excellent resistance to oils and chemicals. A good example is the AS-i Bus TPE Cable.
How These Elements Work Together
The anatomy of a bus cable is not just about individual components but about how they work in synergy. Conductors deliver low-loss signal transmission. Shielding protects against electrical noise. Impedance ensures network compatibility. Jackets safeguard against environmental hazards. Together, these elements make bus cables reliable solutions for demanding industrial and automation environments.
FAQs About Bus Cable Anatomy
Q1: Why does shielding matter so much in bus cables?
A: Shielding reduces electromagnetic interference (EMI) and ensures error-free data transmission, especially near motors and heavy machinery.
Q2: Can I use a PROFIBUS cable in a CAN-Bus system?
A: No. Each bus protocol requires specific impedance. Using the wrong cable can cause signal reflection and communication failures.
Q3: Which is betterꟷPVC or PUR jacket?
A: PVC is economical and suited for stationary installations. PUR is better for flexible, dynamic environments.
Q4: How do I know if my cable is failing?
A: Signs include intermittent communication errors, visible jacket cracks or shield damage.
Q5: Is TKD Kabel a trusted brand for bus cables?
A: Yes. TKD Kabel is a globally recognized brand for high-quality industrial-grade cables.
The anatomy of a bus cable’s conductors—shielding, impedance and jacket materials—determines its performance, reliability and lifespan. In industrial automation, choosing the right bus cable isn’t just about cost; it’s about ensuring uninterrupted communication and productivity.
If you’re looking for robust, reliable and field-tested solutions, explore TKD Kabel bus cables. From PROFIBUS to CAN-Bus to AS-i Bus, the right choice will maximize uptime and minimize risks.
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.
