2 Need faster communication? TI Ethernet PHYs can help

Ethernet PHY transceivers can help address these common challenges. Compared to older communication types, Ethernet provides the fastest and most deterministic communication possible.

The typical control loop for SSTs has a refresh rate of 100 microseconds (10kHz). Depending on the data interface, legacy communications have been with CAN, LIN, or RS-485. However, these communication data rates only reach up to 500kbps-1Mbps. Ethernet can provide a faster communication chain capable of up to 1Gbps data rates. These data rates are also consistent up to 15m for specific types of ethernet and up to 100m for the most common type of Ethernet. This is a significant upgrade in bandwidth and distance over CAN, LIN, and RS-485.

Compared to the older communication topologies, there is an intrinsic delay due to the implementation of the network. From commander-responder acknowledgements to other bus artifacts, it takes a non-deterministic time for sending data between nodes in a multidrop environment. This makes synchronization difficult for the control loop within the SST. With most Ethernet topologies being point to point, the latency becomes much more deterministic and is in the order of nanoseconds to microseconds depending on device. In addition, there are real-time real-time communication systems such as EtherCAT for system synchronization which can enhance ethernet communication at no extra hardware cost on the PHY subsystem. In an EtherCAT system, the topology is point-to-point across a daisy chain compared to multidrop.