The M-bus IoT gateway can be used in various ways:

M-Bus IoT gateway with wired M-bus devices

The M-bus IoT gateway reads up to 20 directly connected devices (20 simple M-bus loads). M-bus devices are connected over line M1M2.

M-Bus IoT gateway with level converters

Up to six level converters (WTV531, WTX631) can be connected in parallel per line to a M-bus IoT gateway.

The level converter (A) is connected to a M-bus IoT gateway via the RS-232 interface (terminals A, B, C). The following level converters (B) can be connected via the M-bus SLAVE connection.

Up to 60 M-bus devices can be connected to each WTV531 level converter.

 

A

Level converter WTV531 (master)

B

Level converter WTV531 (slave)

Up to 250 M-bus devices can be connected to each WTX631 level converter.

UP to six level converters WTX631 (one level converter, five repeaters) or up to two level converters WTV531 (one level converter, one repeater) can be connected in series to a M-bus IoT gateway.

 

M-Bus IoT gateway with wireless devices

The M-bus IoT gateway is equipped with additional RF converters to extend the system up to 2,500 wireless devices. The communication between the M-bus IoT gateway and RF converters takes place over a mesh RF protocol (backbone network).

A minimum of one M-bus IoT gateway and one RF converter is required to read out wireless devices. The backbone RF network can consist of a maximum of 23 RF converters. Communication between the RF converters and wireless devices takes place over the wireless M-bus protocol. The RF converter saves the consumption data from the devices in its environment, while forwarding the data to other RF converters, up to the M-bus IoT gateway (the other RF converters act as repeaters here).

 

M-Bus IoT gateway with network nodes

WT.. network nodes receive telegrams from consumption meters.

Up to 12 network nodes can communicate with each other on a network and exchange the respective consumption data (mesh system). This way, up to 500 heat cost allocators and/or wireless heat/water meters can be incorporated in a radio network (manages 500 addresses). This means that each individual network node stores all consumption data for the entire network.

One M-bus IoT Gateway can read up to 5 networks in parallel. At least one of the WT.. network nodes must be connected to M-bus IoT gateway using a physical M-bus line.

The M-Bus primary address for the connected WT.. Network node is 253.

Up to 20 simple M-Bus loads can be connected via line M1M2 without an additional level converter. A level converter is required, however, as soon as the network nodes are connected via line ABC.

 

 

 

NOTICE
Additional electrical consumption

Shorter lifecycle of network nodes

Reading out device data on the network node via M-bus IoT gateway requires additional electricity. This reduces the lifecycle of battery-operated WT.. Nodes compared to other network nodes on the network.

We recommend reading out the network nodes at most once a day since reading out data can increase battery use by ca. 5%.

NOTICE
Read out a WTX16.. gateway via M-bus IoT gateway
  1. Disconnect communications directly on the WTX16.. between the devices upper section (gateway) and the lower section (network nodes, if you intend to read out an existing wireless network with the WTX16.. gateway via the M-Bus IoT gateway. Parallel reading is not possible and can destroy the devices.
  1. Connect the M-bus IoT Gateway to the network nodes (lower section). The network nodes are still powered with voltage in the upper section.

M-Bus IoT gateway with level converters and district heating controllers

Up to 250 RVD2.._district heating controllers can be connected per line to a M-bus IoT gateway. The M-bus IoT gateway and RVD2.. controllers communicate over M-bus.

NOTICE

In the event M-bus devices (e.g. meters) and district heating controllers are connected to the same line, operate the devices without batteries (AC/DC 24 V, AC 230 V).

Using battery-powered devices may significantly reduce the life of the batteries due to the frequency of the readouts of district heating controllers.

Combined plants

The M-bus IoT gateway can read up to 500 wired and 2,500 wireless devices.

 

A

M-bus IoT gateway (master)

B

Level converter WTV531 (slave)

C

The RF converter as participant on the backbone mesh network and connected to the wireless devices

 

A

M-bus IoT gateway (master)

B

Level converter WTX631 (slave)

C

The RF converter as participant on the backbone mesh network and connected to the wireless devices

D

Level converter WTX631 as repeater to overcome large distances

1

Parallel connection for level converter WTX631

2

Serial connection for level converter WTX631

Readout data

A PC/Internet browser reads the data on all operating modes either locally over Ethernet or from anywhere over the Internet using a PC/Internet browser.

Write RVD parameters

The following parameters can be written to the controllers depending on the connected controller and the corresponding plant image:

Designation

RVD23x

RVD24x

RVD25x

RVD26x

DHW temperature nominal value

X

X

X

X

DHW temperature reduced setpoint

X

X

X

X

Temperature difference solar on

X

X

X

X

Temperature difference Solar off

X

X

X

X

Date of the first day of the heating period

X

X

X

X

Date of the last day of the heating period

X

X

X

X

Heating limit ECO heating circuit 1

X

X

X

X

Room temperature reduced setpoint heating circuit 1

X

X

X

X

Room temperature setpoint, holiday mode/frost protection HC1

X

X

X

X

Heating curve parallel shift, heating circuit 1

X

X

X

X

Heating limit ECO heating circuit 2

-

X

-

X

Room temperature reduced setpoint heating circuit 2

-

X

-

X

Room temperature setpoint holiday mode/frost protection heating circuit 2

-

X

-

X

Heating curve parallel shift, heating circuit 2

-

X

-

X

Legionella function, frequency

X

X

X

X

Time

X

X

X

X

Scheduler, heating circuit 1 Monday

X

X

X

X

Scheduler, heating circuit 1 Tuesday

X

X

X

X

Scheduler, heating circuit 1 Wednesday

X

X

X

X

Scheduler, heating circuit 1 Thursday

X

X

X

X

Scheduler, heating circuit 1 Friday

X

X

X

X

Scheduler, heating circuit 1 Saturday

X

X

X

X

Scheduler, heating circuit 1 Sunday

X

X

X

X

Scheduler HC2 Monday

-

X

-

X

Scheduler HC2 Tuesday

-

X

-

X

Scheduler HC2 Wednesday

-

X

-

X

Scheduler HC2 Thursday

-

X

-

X

Scheduler HC2 Friday

-

X

-

X

Scheduler HC2 Saturday

-

X

-

X

Scheduler HC2 Sunday

-

X

-

X

Scheduler DHW Monday

X

X

X

X

Scheduler DHW Tuesday

X

X

X

X

Scheduler DHW Wednesday

X

X

X

X

Scheduler DHW Thursday

X

X

X

X

Scheduler DHW Friday

X

X

X

X

Scheduler DHW Saturday

X

X

X

X

Scheduler DHW Sunday

X

X

X

X

Integrating a M-bus IoT gateways in Synco IC

The M-bus IoT gateway activation key is entered on the Synco IC-Portal to register the M-bus IoT gateway on the cloud. The activation key is available both via web browser as well as on the M-bus IoT gateway display.

After registration, invoicing and trend data as well as alarm messages can be periodically uploaded per settings and distributed to various users.

The Synco IC-Portal is located at: https://www.siemens-syncoic.com/.