Industrial multi-drop Ethernet controllers with MII or MAC interface
The NCN26000 Ethernet controller from onsemi is IEEE 802.3cg compliant and supports industrial multi-drop Ethernet by integrating all physical layer functions needed to transmit and receive data over a single unshielded twisted-pair.
Communication to existing half-duplex 10Mb/s Ethernet MAC controllers is via a standard MII interface.
The enhanced noise immunity mode extends the noise immunity to values which are significantly above the values in the IEEE T1S standard. This allows the NCN26000 to withstand worst-case immunity tests for direct power injection (DPI) and brain-computer interface (BCI). When enabled, the result is a significantly improved network reach which offers an almost 2x improvement over alternative controllers.
By offering best-in-class line pin capacitance, the NCN26000 supports the highest number of nodes per segment, with 40 nodes on a 25-meter segment. This is above the IEEE standard for the minimum number of nodes and means that the costs for cabling, connectors, and installation are lowered.
The use of collision detection masking allows the NCN26000 to operate in noisy conditions, and prevents false collision detection in high-noise environments.
Physical layer collision avoidance (PLCA) supports higher throughput in multi-drop topologies and lower PLCA IDs are given precedence over higher PLCA IDs. The arbitration that is provided is similar to CAN, as the head node sends a new beacon when any station transmits.
The NCN26000 Ethernet controller communicates over MII, and the NCN26010 offers communication over a media access controller (MAC).