M-Bus

M-Bus (Meter-Bus) is a field bus that was specially developed for recording consumption data. Via a two-wire line protected against polarity reversal, data is usually transmitted at a speed of 2400 Baud. The topology is irrelevant (star, serial or a combination of both are possible).

This chapter describes how you can configure the M-Bus service on the Beetle and start a network query via M-Bus.

Please ensure that your Beetle is in operation and has a connection to the Avelon server. If this is not the case, start in the chapter Connectivity.

Note

A master station supplies the bus with power and transmits data via the field bus. Usually the master station is a level converter with a 9-pole D-sub socket for the connection of serial RS232 interfaces.

The following instructions will guide you through the installation process.

Connect hardware

The M-Bus level converter is connected directly to the Beetle via the COM1 port.

Enable M-Bus service

In order to use the M-Bus service and read network objects, a valid licence key must be stored and the service must be enabled. How to enable or license communication protocol services is described in section Communication protocols.

Configure M-Bus service

Note

To configure the M-Bus service, you must have operator privileges.

  1. Click on M-Bus on the left.

  2. Click on the Configure button to open the configuration dialog of the M-Bus service and edit parameters. The following settings are available:

    Setting

    Option

    Description

    M-Bus Controller

    Transparent (Pure Level Shifter)

    When operating with transparent level converter

    Aquametro

    Bus controller from Aquametro

    NeoVac Bus Controller

    Bus controller from NeoVac

    USB/Serial Converter

    /dev/serport

    Port of the level converter

    M-Bus Protection Time

    • (None)

    • 15 Minutes

    • 1 Hour

    • 6 Hours

    • 1 Tag

    • 1 Woche

    • 2 Wochen

    Time interval in which the readout must not be repeated

The data transmission rate is set to the default value of 2400 baud as defined in EN 1434.

The protection time is the time interval in which no further data queries may take place. This time interval is specified by the system manufacturer, for example, for battery-powered meter systems. The recommended default value is 1 day.

Scan bus

On the M-Bus page, enter the desired scanning parameters and then click the  Discover devices button to start a bus scan.

Setting

Option

Description

Scan Address

Primary Address

A targeted search for addresses is performed

Secondary Address (ID)

A targeted search for IDs is performed

Scan Range

All

Query all addresses

Range

Query a specified address range

Single

Query a single address

Range/Address

From/To

Start and end address

Address/ID

Single address or ID

Note

If you receive the message “Please start the M-Bus service to display objects on the network.”, you must first enable the M-Bus service (see Enable M-Bus service).

After a short time, all network devices found are displayed. Select one of the found devices to query its objects. Use this list to check whether all objects were found as expected. Only then you should adjust the data points via the Avelon user interface.

Warning

Except for device discovery, Avelon always uses the primary address to communicate with M-Bus devices. The reason being that if meters are replaced while keeping the same primary address, they will continue to work seamlessly.

Download data point list (optional)

After a successful network scan, click the  Download button to download the list of found objects to your computer as a CSV file.