10Base-T1S Network Technology in SPE (Single Pair Ethernet)

Date: 29 May 2026

Complied By: Owen Zhang (FAE Manager)

The essential difference between 10Base-T1S Ethernet and traditional Ethernet is the use of PHY layer technology incorporating PLCA (Physical Layer Collision Avoidance), which operates as a half-duplex communication system.

Principles of PLCA Technology

• It is essentially a sequential polling communication mechanism that assigns a unique ID to every node in the network and polls them in order according to their ID.

• It specifies a fixed time for each node to send or receive data or commands.

• The entire communication process is initiated and coordinated by a PLCA coordinator (usually node ID 0), which sends a Beacon signal to mark the start of a communication cycle.

   

Core Characteristics

• Communication timing and latency are deterministic; prior to the initiation of a communication cycle, all timing and latency across network nodes can be accurately predicted and calculated.

• The communication cycle consists of: Beacon + Data Frames for each node + Silent period.

• Beacon and Silent durations are fixed, while frame duration is determined by the length of the data carried within the frame (data length ranges from 64 Bytes to 1536 Bytes).

• Therefore, while the time and latency of a single T1S communication cycle vary depending on the number of nodes and data volume, the overall cycle is deterministic and predictable.

   

Application Highlights

• Topology: Nodes are daisy-chained via a single twisted-pair cable before connecting to a switch, significantly reducing the wiring complexity of star network topologies.

• Capacity/Range: Supports up to 50 nodes, with a maximum distance of 2m between nodes; the total network cable length cannot exceed 100m, categorizing it as short-range communication.

• Compatibility: Can be seamlessly integrated into traditional Ethernet via switches.

   

MCHP 5 Categories of T1-S Chips

• Comparison with Other Network Buses

T1S vs. RS-485 / CAN / Modbus:

T1S can avoid network collisions at the physical layer entirely.

T1S supports precise 1588 time synchronization protocols and PoE (Power over Ethernet), which other buses cannot do.

T1S is seamlessly compatible with traditional IT networks without the need for a gateway, making it highly suitable for automotive or industrial data-to-cloud requirements.

T1S vs. EtherCAT:

All nodes on a T1S network bus are equal; unlike EtherCAT, there is no master-slave relationship.

T1S does not require a gateway for seamless compatibility with traditional Ethernet, whereas EtherCAT requires gateway support.

T1S solutions are more cost-effective than EtherCAT, and the chips are significantly smaller in both cost and volume.

Applications

• Automotive: Interconnection of various internal systems such as motors, lighting systems, audio systems, power trains, and domain controllers.

• Industrial Automation: Interconnection and cloud connectivity for sensors, actuators, alarm systems, HVAC, and refrigeration equipment.

• Systems: Elevator systems, robotics, and energy storage system management/monitoring in smart energy.

• Data Centers: Management and monitoring.

• Medical: Interconnection and monitoring/management of medical equipment in hospital wards, operating rooms, and laboratories.