IEEE 802.3cg-compliant ICs bring Ethernet to edge of factory networks

Factories today commonly use Ethernet networks for supervisory control and station management, but still rely on legacy fieldbus solutions to communicate with field instrumentation. Such legacy protocols need to be replaced and modernized with low-cost, single unshielded-pair Ethernet solutions which will allow factories to run data over Ethernet seamlessly from the cloud to the edge.

The IEEE 802.3cg standard provides a specification for the technology to overcome the gap in industrial Ethernet systems, offering low-cost communication to field devices at a data rate of 10 Mbits/s using two physical layers: 

• 10BASE-T1L for long-range, point-to-point communication over a range of up to 1,000m 
• 10BASE-T1S for multi-point communication over a range up to 25m

Now onsemi has introduced dedicated IEEE 802.3cg-compliant components which provide a robust, off-the-shelf solution for unshielded-pair Ethernet. 

The NCN26000 is an Ethernet transceiver (PHY) which provides all the physical layer functions needed to transmit and receive data over a single unshielded twisted-pair cable. The transceiver communicates to half−duplex 10Mbits/s-capable Ethernet controllers via a standard MII interface.

The NCN26010 Ethernet incorporates both an Ethernet media access controller (MAC) and a 10BASE-T1S PHY for data communication over a single unshielded twisted-pair cable. The NCN26010 communicates to a host microcontroller via an Open Alliance MACPHY SPI protocol.

The noise immunity of the NCN26000 and NCN26010 is far higher than is specified in the 10BASE-T1S standard: a proprietary enhanced noise immunity feature provides robust signal detection in noisy industrial environments, and can extend the network range to up to 50m. The NCN26000 and NCN26010 also offer very low line capacitance, enabling them to support five times the node requirement of the IEEE 802.3cg standard, up to 40 nodes on a 25m segment. This helps factory operators to save more on the cost of wiring and installation.

Multi-drop Ethernet offers a way to reduce the wiring and installation costs which dominate the networking budget in many factories: a network can be completed with up to 70% fewer cables while reducing installation costs by as much as 80%. 10BASE-T1S also offers the flexibility to repurpose nodes after the initial installation.

Additional benefits include: 

• Eliminates the need for large switches, gateways, or protocol translators, and the additional wiring and power that are required
• Lowers software maintenance costs as multiple networking technologies no longer need to be maintained, as legacy point-to-point and multi-point standards, such as RS-485, CAN, FlexRay, RS-232, or HART may be replaced by 10BASE-T1S Ethernet
• Enables greater data throughput over existing cables, eliminating the need to run new cables, which is often the highest contributor to costs in a networking installation