If you only use the purchase cost when comparing the implementation of an SPE network with a traditional network, you cannot determine the true cost of ownership.Calculating the Total Cost of Ownership of an SPE. Four phases need to be considered throughout the network's lifecycle:
01 Acquisition
02 Commissioning (distinguishing between hardware installation and software setup)
03 Operation
04 Maintenance
When comparing the implementation costs of an SPE network with traditional networks based on fieldbus or serial interfaces, the purchase cost is often the only expense considered. The costs and benefits of subsequent lifecycle phases, such as commissioning, operation, and maintenance, are rarely included. When calculating equipment costs, the price of Ethernet transceivers and additional circuitry (magnetic components) is often compared to the price of a simple RS-485 or RS-232 interface. However, to determine the true total cost of owning an SPE network, it is essential to consider all four installation phases in more detail.
Smooth Communication:
From sensors to the cloud, SPE enables seamless machine-to-machine and machine-to-human communication. The transparent Ethernet-based network supports IP-based communication between end nodes. Heterogeneous networks require gateways to connect network segments that restrict the visibility and accessibility of end nodes.
High bandwidth:
Using only one pair of wires for transmission, SPE's data throughput ranges from 10 Mb/s to 1 Gb/s over different distances (data throughput decreases with increasing distance).
Long transmission distance:
Compared to other technologies, SPE can maintain higher data speeds over longer distances. Distance related to bandwidth is sometimes referred to as the "bandwidth range." Remote power supply capability: SPE can transmit power via a combination of data cores or additional cores in the cable, enabling remote power supply (separate power supply from the device).
Installation flexibility:
Compared to traditional four-pair cables, SPE cables have a smaller diameter based on conductor cross-sectional area, making installation in confined spaces such as control cabinets faster and easier.
Possibility of using SPE at the sensor/actuator level:
To meet the different requirements of various target markets for SPE, equipment manufacturers have defined different bandwidth, cable length, and topology standards for the physical transport layer.
There are various industry protocols for higher layers, as well as a variety of connectors to complement different industrial environments, and their requirements for:
dust and moisture resistance
chemical resistance
robustness against mechanical stress and electromagnetic interference (EMI)
Given the numerous combinations of requirements, active infrastructure component and end-device manufacturers may address this complexity by offering solutions with economically viable cost/benefit ratios, but only applicable to certain applications.
Early standardization and the establishment of universal industry standards, while potentially slowing the overall adoption of SPE networks and technologies, are a possible way to overcome this problem.
Manufacturers must also confront the fact that electronic components have already been developed for automotive applications. Their implementation requires additional effort. A prominent example is the switches and multiport transceiver (PHY) chips for SPE offered by semiconductor manufacturers.
For example, currently, RGMII, RMII, or MII (Media Independent Interface) are required to connect switches and single-port PHY chips. The large number of signals at these interfaces, coupled with the use of single-port PHY chips, leads to more complex signal routing on the PCB and increased space requirements.
While modern interfaces (such as SGMII) require 4 signals per port, MII interfaces require 16 signals and RMII interfaces require 8 signals. Furthermore, each single-port PHY chip also requires MDIO and MDC management interfaces.
Currently, there are no SPE multi-port PHY chips equipped with suitable media-independent interfaces (such as SGMII or QSGMII). Specifically, for 10BASE-T1L, these interfaces designed for gigabit operation are not an area of focus for semiconductor manufacturers. However, the development of switch ASICs is driven by rapidly growing bandwidth demands, and therefore, corresponding MAC-PHY interfaces with multi-gigabit bandwidth are being optimized.
SPE brings innovative potential to professionals involved in all four phases of the network installation lifecycle. This is strongly reflected in the various standardization activities of IEEE and user organizations.
Despite IEEE's long history of standardization, SPE is still a relatively young technology and will primarily prove itself in more complex and intelligent sensors before being applied to simpler ones. As the availability of components and hardware continues to improve, SPE will continue to hold its place in the market for cheaper sensors and ensure the coordination of network components.