Eclipse Kura introduces a model based on the concepts of Drivers and Assets to simplify the communication with the field devices attached to a gateway.

A Driver encapsulates the communication protocol and its configuration parameters, dealing with the low-level characteristics of the field protocol. It opens, closes and performs the communication with the end field device. It also exposes field protocol specific information that can be used by upper levels of abstraction to simplify the interaction with the end devices.

An Asset is a logical representation of a field device, described by a list of Channels. The Asset uses a specific Driver instance to communicate with the underlying device and it models a generic device resource as a Channel. A register in a PLC or a GATT Characteristic in a Bluetooth device are examples of Channels. In this way, each Asset has multiple Channels for reading and writing data from/to an Industrial Device.

Channel Example

To further describe the concept of Channel and Asset, the following table shows a set of PLC register addresses as provided in a typical PLC documentation.

Name Entity Address
LED1 COILS 2049
LED2 COILS 2050
LED3 COILS 2051
LED4 RED COILS 2052
LED4 GREEN COILS 2053
LED4 BLUE COILS 2054
Counter 3 INPUT REGISTERS 515
Quad Counter INPUT REGISTERS 520
Toggle 4 DISCRETE INPUTS 2052
Toggle 5 DISCRETE INPUTS 2053
Toggle 6 DISCRETE INPUTS 2054
Reset Counter 3 COILS 3075
Reset Quad Counter COILS 3084

The corresponding Channels definition in the Asset is as follows:

channels

As shown in the previous image, the Channel definition in an Asset results easily mappable to what available in a generic PLC documentation.

Once defined the Channels in an Asset, a simple Java application that leverages the Asset API can easily communicate with the Field device by simply referring the specific Channel of interest.

Drivers and Assets in ESF Administrative UI

Kura provides a specific section of the UI to allow users to manage the different instances of Drivers and Assets. Using the Kura Web UI the user can instantiate and manage Drivers

driver_config

but also can manage Assets instances based on existing drivers.

asset_config

The user interface allows also to perform specific reads on the configured Assets’ channels clicking on the Data tab for the selected Asset.

asset_data