Eurogard Node-Red BACnet Nodes

Experimental development implementation of a Node-RED node that makes BACnet accessible by defining an API to communicate with a BACnet network through an edge device, such as the Eurogard ServiceRouter, using websockets for transport.

Built in the context of bawebcontest research project.

The design is loosely based on the structure of the s7 contrib node.

As this is a design draft, expect bugs and missing features. If you possess an edge device implementing the defined API, most functionalities should operate correctly.

Be aware that the API may change in the future.

Setup

Note that the provided Makefile should allow you to execute these tasks without manual copy-pasting. Both Npm and Node are required to be installed on your system. Running make from the project root should list available commands and their descriptions.

Local Install

cd $DIR; # change to project root
npm install;
npm test; # run tests
npm start; # start Node-RED

Using Docker

A basic compose file and a Dockerfile are provided. The docker image builds upon the official Node-RED image, integrating the BACnet nodes and the BACnet Node-RED contrib node.

docker compose up -d

Project Structure

Our aim is to match the general structure of the s7 contrib node.

• We define three primary Node-RED Nodes:

• bacnet_read

• bacnet_write

• bacnet_info

bacnet_read

This node retrieves actual data from BACnet devices. Users should be able to choose:

• from a list of datapoints from a specific device
• all datapoints from a device
• all datapoints from all known devices

Subsequently, users can decide how they want to process the data using the standard Node-RED tools.

bacnet_write

This node writes data to BACnet devices. Users should be able to send incoming values (in JSON format -> adhering to the "Node-RED-JSON-inter-node-communication-standard") to one or more BACnet devices, as long as the datapoints are distinctly identified. This uniqueness is assured if they use the eurogard-flask-bacnet datapoint UIDs.

bacnet_info

• Retrieve device information for any number of devices
• Follow the Eurogard-BACnet-flask implementation of "registered_devices":
• registered_device:
  • can be online or offline
  • datapoints only accessible when online
  • caches written values when offline, and updates cached values when returning online
• online_device:
  • must be registered to be accessible
  • only exists when online

Command Documentation

We recognize 4 types of input parameters (apart from the command string):

1. Devices:

   {"devices": List[String]}

2. Datapoints:

   {"devices": Devicepath->Map[String]: Datapoints->List[String]}

3. Values:

   {"devices": Devicepath->Map[String]: Datapoints->Map[String]: Primitive Datatypes->[Int|String|Bool]}

4. No input parameters

If the "Read command from input" option is checked, we anticipate an additional key:

{"command": Command->String, "devices": ...}

The subsequent commands are established:

bacnet in

• "write"

  • "Write value",
  • Expected Input: "values"

• "from_input"

  • "Read command from input",
  • Expected Input: None

bacnet out

• "reads"
  Read value

  • Expected Input: List of "datapoints"

• "reads_onlyone"
  Read only one value

  Expected Input: datapoint

• "from_input"
  Read command from input instead of msg.payload

  • Expected Input: None

bacnet control

• "from_input"
  Read command from input

  Expected Input: None

• "online"
  Scan for online devices

  Expected Input: None

• "enumerate"
  Read BACnet config from edge device and enumerate devices

  Expected Input: None

• "config"
  Obtain BACnet Information

  Expected Input: None

• "deviceinfo"
  Acquire device Information

  Expected Input: List of devices

• "datapoints"
  Fetch data point list of a device

  Expected Input: List of devices

• "helloworld_from_nodered"
  Sends a friendly _Hello World to the configured edge device

  Expected Input: None