Hardware

This chapter covers hardware related topics around OpenEMS Edge. It describes how physical hardware is abstracted using Natures, how standardized physical connection layers and protocols are implemented using Bridges and shows which Devices and Services are implemented. The chapter concludes with a development tutorial on how to implement a device.

1. Natures

Physical hardware is abstracted in OpenEMS Edge using Natures. A Nature defines a set of characteristics and attributes which need to be provided by each OpenEMS component that implements it. These characteristics are defined by Channels. For example an implementation of an Ess (Energy Storage System), needs to provide an Soc-Channel (State of charge of the battery).

Technically Natures are implemented as OSGi API Bundles.

1.1. ESS (Energy Storage System)

An Energy Storage System is an integrated system with battery and battery inverter.

Ess

A generic Energy Storage System

SymmetricEssReadonly

A symmetric Energy Storage System in readonly-mode.

A symmetric, controllable Energy Storage System.

EssDcCharger

A solar charger that is connected to DC side of an energy storage system.

1.2. Meter

Meter

A generic electric power meter.

SymmetricMeter

A power meter for symmetric metering.

AsymmetricMeter

A power meter for asymmetric metering.

1.3. EVCS (Electric Vehicle Charging Station)

Evcs

A charging station for electric vehicles like e-cars and e-buses.

1.4. I/O (Digital Input/Output)

DigitalOutput

One or more digital outputs or relays.

2. Bridges

To simplify the implementation of hardware that is connected via certain standardized physical connection layers and protocols, those are implemented as Bridges.

2.1. Modbus/TCP

Modbus/TCP

Modbus/TCP is a widely used standard for fieldbus connections via TCP/IP network. It is used by all kinds of hardware devices like photovoltaics inverters, electric meters, and so on.

2.2. Modbus/RTU

Modbus/Serial

Modbus/RTU is a widely used standard for fieldbus connections via RS485 serial bus. It is used by all kinds of hardware devices like photovoltaics inverters, electric meters, and so on.

3. Devices & Services