Wmbus-client NPM

wmbus-client

Wireless M-Bus client is a JavaScript library for reading, logging, processing and distributing wM-Bus meter telegrams.

This experimental IoT-project aims to provide basic meter reading and reporting. Collected data can be logged or distributed to external services over internet, making your environment to be part of Internet of Things.

Meters and readers

Wireless M-Bus meter is a device that measures for example water or gas consumption. After reading the value, meter sends this information in small packets called radio-telegrams. Radio frequency and telegram structure depends on your meter type and and so called Mode.

To be able to collect data you need a physical wM-Bus reader. Reader is a device that listens radio telegrams and broadcast this data for your computer.

Incoming telegrams are usually well formatted using schemas and frames. But because there is no one standard for the payload, the actual content may vary from meter type and manufacturer. Usually large amount of information is coded into few bytes and it might not be easy to find out how the data should be decoded back to something meaninful.

Usually the payload of telegram is encrypted using AES and you need the meter specific secret key to be able to decrypt the data.

Collecting and processing wM-Bus data

This library provides util components for some known meters and readers.

Incoming data from reader device is buffered by "Reader component". Intact raw telegrams can be processed from queue. Usually this data is stored and logged, or it can be sent over the internet.

To be able to parse data from certain telegram we need low level support for the particular manufacturer and meter. This is called "Meter component", which reads telegrams from our Reader component and converts the information from payload to something meaninful, like current temperature or total water concumption.

Usage

TODO: Add more examples how to use configuration.

Here is example configuration for meters you are about to read. You need to specify manufacturer name, serial number, version and device type. These fields are known as Meter ID, which is an unique identifier for single meter.

If telegram payload is encrypted, you need also AES key.

// meters.json
[
  {
    "manufacturer": "KAM",
    "serial": "00000000",
    "version": "1b",
    "deviceType": "06",
    "aes": "0000000000000000",
    "label": "My meter"
   }
]

Supported meters and readers

At the moment it supports Kamstrup Multical 21 water meters and AMBER wM-Bus Module AMB8465-M. It should work also with other Amber modules like AMB8426-M, AMB8626-M, AMB3626-M and AMB3636-M.

Please contribute to get more readers and meters.

Example application

This repository contains simple example application to demonstrate how to use reader. Application just collects data and prints out the readings. Collected data is also stored to csv log gile.

To collect data, run application with command:

    $ READER_METHOD=collect node run-consumption-example.js

This will create a log file using current date timestamp and stores meter telegram.

To analyze overall consumption from old stored log files, you can start app with environement value 'log'. This will read telegrams from log files, and prints out the overall consumption from very first telegram to latest one.

Note: At the moment you need to manually provide a list of log files, see configuarion examples below.

    $ READER_METHOD=log node run-consumption-example.js

Example application contains some configuration:

let example = new Example().run({
  // Meter configuration path
  configurationPath: './../../data/meters.json',
  // Log writer path.
  // The extension will be .log and there will be date based suffix.
  logWriterPath: './../../data/consumption-export',
  // Serial port path
  serialPortPath: '/dev/cu.usbserial-2701A795',
  // Interval to check buffer status
  bufferInterval: 20,
  // Preview interval
  previewInterval: 60000,
  // If READER_METHOD env variable is 'log', we just read provided log files and
  // print out the total consumption between first and last reading.
  logReaderSource: [
    './../../data/consumption-export--20170103.log'
    './../../data/consumption-export--20180114.log',
    ],
  // CSV log path
  csvFile: `./../../composed/composed--${moment(Date.now()).format("YYYYMMDD-HHmmss")}.csv`,
  // Reader type: 'collect' or 'log'
  readerType: process.env.READER_METHOD ? process.env.READER_METHOD : 'collect'
  }