Edge X Foundry Logical Layers
Edge X Foundry is a collection of open source microservices. Logistically, the microservices are organized into four layers and two underlying augmenting system services.
Device Services Layer
Device Services (DS) are the edge connectors serving at the "south side" of Edge X Foundry. "South side" means the part of the network that communicates directly with devices, sensors, actuators, and other IoT objects. The Microservices on the Device Services Layer communicate with devices, sensors, actuators, and other IoT objects through the protocol native for that object. The DS Layer takes the data produced and communicated by the object and converts the data into a common Edge X Foundry data structure and sends that converted data into the Core Services Layer for use in Edge X Foundry, and other microservices in other layers of Edge X Foundry.
For example, a BACNet DS converts the BACNet device-supplied temperature and humidity readings into a common Edge X Foundry object data structure. A DS also receives and translates commands from other Edge X Foundry services or enterprise systems and communicates that request to the devices for actuation in a language that the device understands. For example, a DS may receive a request to turn off a Modbus PLC controlled motor. The DS would translate the generic Edge X Foundry "shutoff" request into a Modbus serial command that the PLC/motor understands for actuation.
A device service may service one or a number of devices (sensor, actuator, an so forth) at one time. A "device" that a DS manages could be something other than a simple single physical device, such as another gateway (and all of that gateway's devices); a device manager; or a device aggregator that acts like a device or collection of devices to Fuse.
Core Services Layer
The Core Services (CS) Layer separates the north from the south side layers at the edge on the gateway. Core services include the following items:
- Core data: a persistence repository and associated management service for data collected from the south side objects,
- Core metadata: a repository and associated management service of meta data about theobjects that are connected to Edge X Foundry
- Core command microservices: a service that facilitates and controls actuation requests from the north side to the south side.
Additionally, the Edge X Foundry registration and configuration service is part of this layer. This service provides other Edge X Foundry microservices with information about associated services within Edge X Foundry and microservice configuration properties.
The metadata service also provides the capability to provision new devices and pair them with their owning device services.
The Core Services Layer at this time, includes the following microservices:
- Data
- MetaData
- Command
- Configuration/Registration
Supporting Services Layer
The Supporting Services (SS) Layer encompass a wide range of microservices that keep Edge X Foundry functioning and provide the edge analytics or intelligence. Normal software application duties such as logging, scheduling, and data clean up (scrubbing) are facilitated by microservice capabilities in the SS Layer.
Additionally, the rules engines and alerting/notification microservice facilities are logically grouped within the SS Layer because they operate on top of the Core Services Layer. The local analytics capability or rules engine is also located in this layer and is a recipient client of the Export Services Layer.
The Supporting Services Layer at this time, includes the following microservices:
- Logging
- Alerts/Notifications
- Scheduling
- Rules Engine
Export Services Layer
Edge X Foundry operates independently of other systems when necessary. Gateways often operate in isolated and sometimes disconnected environments and monitor and manage a collection of sensors and devices that have little or no outside monitoring or control. Therefore, Edge X Foundry can operate and sustain itself over long periods of time without connection to the "north side" systems. However, it is preferable to have the data and intelligence collected and created at the edge transported to enterprise (cloud) systems frequently, and the Export Services (ES) Layer performs this function. The ES Layer provides a set of microservices that enable off-gateway clients to register for data of interest coming from the south side objects, and inform where and when the data is to be delivered, and the format and shape in which that data is to be delivered. For example, the where and when could be to send temperature data to a REST address every hour, and the format and shape could be to supply JSON data in compressed form.
The Export Services Layer at this time, includes the following microservices:
- Client Registration
- Distributor
Security Infrastructure
Security elements both inside and outside of Edge X Foundry protect the data and command of devices, sensors, and other objects managed by Edge X Foundry.
System Management
System management facilities provide the installation, upgrade, start, stop, and monitoring of Edge X Foundry microservices and BIOS firmware, operating system, and other gateway-related software, and can also support these functions from off-box, enterprise-based systems.