ZeroWire How It Works
 

In most systems, the standard command and control signals are carried over wiring frequently referred to as the “communications bus.”  For DC voltage systems, this wiring is often based on LIN or CAN-bus.  With rapidly increasing demands on electrical systems, both LIN and CAN-bus have become limiting technologies.  They require separate wiring for communications - wiring that is in addition to that which provides power.  They also have to be isolated and protected from other subsystems.

 

ZeroWire works over the DC “power bus.”  The power bus provides electricity to the various components and travels from the source (battery, generator, etc.) to the load (lights, horns, gauges, etc.), and back to the source through ground, neutral or return wires.  ZeroWire communicates data and command signals through a capacitive connection to the power bus.  As this is the same bus that supplies power to all loads in the system, ZeroWire can greatly reduce the amount of wiring, providing true multitasking capability.

 

The DC Challenge

While conducted emissions have been done over alternating current (AC) wiring with some success, many systems use low voltage DC for power.  Sending communications and control messages over DC power wiring is problematic in that DC is susceptible to many types of noise from sources such as motors, solenoids, generators and some types of lights.  In addition, more powerful radiated emissions (from wireless devices) can also attach themselves to a conductive path. The powerline is by its nature a very difficult communication channel. Its impedance may change unexpectedly.

 

The powerline is noisy with high impulses generated by the loads on the line that may reach 100V. To address this challenge, the ZW solution utilizes data coding with a narrow band phase modulation carrier. The ZW technology works by combining electronic filtering circuits with the advanced algorithms of the Esker proprietary transceiver into adaptable modules. These modules can be deployed on to the DC power bus or incorporated into other devices. The modules can be easily rearranged or redeployed as needed.

 

This technology supports serial data protocols (UART and SPI) to interface with data processing equipment. Data entered from any data entry source is buffered in a Transmit FIFO, translated into packet message, and coded by Error Correction Codes. ZeroWire can be configured to interface with current communication protocols including CAN-bus.