The Problem: Too Many Buses, Too Much Complexity

Walk into any factory, server room, or building-automation cabinet and you’ll find the same story: a tangle of incompatible industrial communication buses. Fieldbus for the PLCs. RS-485 for the sensors. SPI, I²C, and UART on the backplane. CAN or LIN in the vehicle harness. Each one comes with its own wiring, connectors, protocol stack, and specialist knowledge.

That fragmentation has a real cost. Every additional protocol means another gateway to translate between networks, another cable specification to manage, and another set of tools your engineering team needs to maintain. It increases bill-of-materials spend, slows integration, and widens the attack surface for security threats.

A Single Bus for All of It

10BASE-T1S, standardized as IEEE 802.3cg, was designed to solve exactly this problem. It is a multidrop Ethernet bus that runs at 10 Mbps, half-duplex, over a single unshielded twisted pair. Up to 50 nodes can share one bus segment of up to 25 meters, no switch required.
 

Because it is native Ethernet, every device on a 10BASE-T1S segment speaks the same IP-based protocol stack used by the rest of your network. That means a sensor on the factory floor, a diagnostic port on a server backplane, and a lighting controller in a building lobby can all use the same software, the same security model, and the same cloud-integration path. The gateways disappear.
 

Collision-Free Sharing with PLCA

A shared bus raises an obvious question: what happens when two nodes try to transmit at the same time? 10BASE-T1S answers this with Physical Layer Collision Avoidance (PLCA). Under PLCA, nodes take turns in a deterministic round-robin cycle. Each node gets a dedicated transmission opportunity, sends its frame in full, and then yields to the next. There are no collisions, no back-off delays, and bandwidth utilization stays high.

This deterministic behaviour also supports functional-safety requirements in applications where predictable, reliable communication is non-negotiable. Think industrial control loops or automotive powertrain networks.

Why It Matters: Fewer Parts, Lower Risk, Easier Scaling

The practical benefits cascade quickly once the bus consolidation is in place, accelerating industrial Ethernet adoption at the network edge:

• Fewer cables, connectors, and switch ports reduce material cost and assembly time.
• A single protocol stack across all speed grades - from a 1000BASE-T1 backbone down to 10BASE-T1S at the edge eliminates gateway hardware and the engineering overhead of maintaining multiple stacks.
• Adding nodes is as simple as tapping into the existing twisted pair. In an elevator system, for example, extending to additional floors means lengthening the bus line, not redesigning the controller. In an automotive platform, optional sensor packages can be offered without changing the central ECU wiring.
• Proven Ethernet security and over-the-air update mechanisms extend all the way to the lowest-cost edge nodes.

Microchip’s 10BASE-T1S Portfolio

Microchip Technology offers a tiered product lineup that makes 10BASE-T1S practical for a range of design constraints:

• LAN865x (LAN8650 / LAN86501): MAC-PHY devices that bundle a Media Access Controller with the Ethernet PHY. These allow even low-cost microcontrollers without an onboard Ethernet MAC to connect directly to a 10BASE-T1S bus over SPI.
• LAN867x (LAN8670/1/2): Standalone PHY transceivers for microcontrollers or processors that already include an Ethernet MAC. Compact and high-performance.
• LAN866x: Endpoint devices using Microchip’s Remote Control Protocol (RCP). These translate Ethernet frames directly to local digital interfaces, removing the need for a microcontroller or software on the edge node entirely, ideal for centralized or zonal architectures.
• LAN8679 / LAN8680: PMD transceivers with TC14/TC10 sleep and wake capabilities for automotive applications.

Getting Started with EPS Global

EPS Global’s semiconductor engineering team has supported Microchip product design-ins for nearly 20 years across storage, telecom, networking, automotive, and industrial markets. Our Field Application Engineers work with you from concept through to manufacturing, providing hands-on guidance on part selection, schematic review, and system integration.

If you’re evaluating 10BASE-T1S for an upcoming design - whether you’re consolidating legacy buses in a factory, simplifying a building-automation network, or adding Ethernet connectivity to an automotive zonal architecture, contact our FAE team to discuss your requirements and get access to evaluation kits and reference designs.

To learn more or request engineering support, visit our semiconductor engineering support page, or contact your local EPS Global office.