10BASE-T1L is currently the most prominent physical layer standard in industrial SPE applications, formally incorporated in IEEE 802.3cg (published 2019). Breaking down its name clearly describes three key specifications: 10 (10 Mbps data rate), BASE (baseband transmission), T1L (single twisted pair, long distance).

Maximum Transmission Distance: 1,000 Meters

This is 10BASE-T1L’s most impressive characteristic. Traditional standard Ethernet (100BASE-TX / 1000BASE-T) is limited to 100 meters, while 10BASE-T1L achieves 1 kilometer on standard quality industrial twisted-pair cable — sufficient to cover most field device-to-control-room distances in large factories or buildings without any repeater equipment.

Only One Wire Pair Required (2 Conductors)

Compared to traditional Ethernet’s 4 pairs or 8 conductors, 10BASE-T1L requires only a single twisted pair for full-duplex communication. This not only dramatically reduces cable cost and weight, but also allows existing PROFIBUS, Foundation Fieldbus, and other legacy wiring to be repurposed, lowering the barrier to migration.

Compatible with Existing Ethernet Protocols

10BASE-T1L only defines the physical layer. Data protocols running above it are fully compatible with standard Ethernet — including TCP/IP, PROFINET, EtherNet/IP, OPC UA, and Modbus-TCP. This means existing software stacks and IT tools can be used directly, with no additional protocol gateways required.

Dual Signal Voltage Modes

10BASE-T1L supports both 1.0 V p-p and 2.4 V p-p signal voltage modes. The former is used in hazardous areas requiring Intrinsic Safety; the latter is used in non-intrinsically-safe environments, tolerating higher cable loss to achieve longer transmission distances.

In summary, 10BASE-T1L provides true ‘Ethernet to the edge’ connectivity for industrial and building field applications at relatively low cost, serving as a critical bridge for IT and OT integration.