Issue link: https://resources.mouser.com/i/1510154
mouser.com/te 11 SPE and the 10Base-T1S Standard A new car today is a computer on wheels, with global connectivity making them IoT devices and hubs. By partitioning a vehicle into zones, zone controllers coordinate all activity from all connected sensors and actuators (Figure 2). Based on physical location instead of domain-based distribution, this hierarchal architecture reduces the number of electronic control units (ECUs) and can reduce the overall length of harness cabling. Reducing wire harness cabling and incorporating lower-cost edge nodes provide substantial cost and weight savings (which is especially crucial to EVs). Subservient nodes under a zone controller can use a lower-cost 10BASE-T network since they don't need the 100MHz bandwidth used between zones. The zone-to-zone network is 100Mbps, and the zone-to- device network (10BASE-T1S) is 10Mbps. This is where the 10BASE-T1S standard fills the gap of Ethernet communications in a car. While zonal controllers can connect with 100BASE-T interfaces, the communications between endpoint nodes at the edge and the zone controllers have centered around the 10BASE-T1S standard. This allows the car's supercomputer to monitor each zone more quickly with a lower probability that a low-priority sensor is chiming in. The microprocessor in each zone can monitor the lower-priority sensors and encapsulate that data in its reporting to the supercomputer. This not only reduces network overhead, it also allows the higher-speed sensors to provide more resolution to the supercomputer, enabling even higher levels of performance and safety. 10BASE-T1S Features 10BASE-T1S uses a shared medium. It is a multi-drop networking topology where each node connects to a single cable. Thus, there is no need for a switch and router and other higher-level networking aggregators and demultiplexers. A key feature of 10BASE-T1S is a single software framework conducted in the vehicle's communication system from lowest to highest speed ranges. The physical layer focuses on reconciliation and data coordination from multiple mediums. The single-pair protocol described by the IEEE 802. cg results in reduced latency with an embedded clock sampled between edges. The Manchester-encoded data uses voltage transitions instead of voltage levels, whereas the absence of a transition transfers data. Another key feature is that 10BASE-T1S supports complete or half-duplex communications and uses galvanic isolation to protect the network from faults caused by individual nodes. Each node is assigned a unique ID, and only that device can transmit during its transmit opportunity, which is allocated in a round-robin, token-passing topology. Figure 2: The hierarchal partitioning of automotive zones allows a high-speed backbone between zones, a supercomputer, and lower-speed networking at the edge. Data from edge devices is aggregated and routed to the supercomputer when needed. (Source: Analog Devices: https://www.analog.com/en/thought-leadership/ why-10base-t1s-is-the-missing-ethernet-link.html)