# M-Bus Serial Communication Setup Guide

### Description

This article describes how to establish communication between WCC Lite and a meter using the Meter-Bus protocol.

### Physical Link Setup: WCC Lite to Meter Connection

<span class="tlid-translation translation" lang="en"><span class="" title="">Set up your computer and connect Ethernet cable to WCC Lite ETH0 port. Login with default credentials and setup basic required settings (name, network, users, etc. ). </span></span>You can find configuration tutorials in [How to](https://wiki.elseta.com/books/how-to) articles.

[![Pav_wcc.png](https://wiki.elseta.com/uploads/images/gallery/2023-12/scaled-1680-/pav-wcc.png)](https://wiki.elseta.com/uploads/images/gallery/2023-12/pav-wcc.png)

The WCC Lite lacks a built-in hardware interface for M-Bus connectivity, requiring the use of an RS485 or RS232 to M-Bus Master Converter for establishing a connection.

In the illustrated example, a Schneider IEM2135 meter was used alongside the M-Bus 10 RS485/M-Bus Master Converter for data exchange.

#### Example

When the meter configuration parameters match the ones in the Excel sheet, communication can be established. In the example, we also set up IEC104\_SCADA communication along with M-Bus for smooth integration with the IEM2135 meter.

Configuration for the example showed in the illustration -&gt; [Download](https://wiki.elseta.com/attachments/574)

The guidelines for creating your own configuration will be presented in the following segment.

### Configuration

##### M-Bus parameters for *Device* tab

<table border="1" id="bkmrk-parameter-descriptio-0" style="width: 100%;"><tbody><tr><td class="align-center" rowspan="2" style="width: 15.7%;">**Parameter**  
  
</td><td class="align-center" rowspan="2" style="width: 8.52993%;">**Type**  
  
</td><td class="align-center" rowspan="2" style="width: 25.4662%;">**Description**  
  
</td><td class="align-center" rowspan="2" style="width: 9.5189%;">**Required  
</td><td class="align-center" rowspan="2" style="width: 11.8656%;">**Default value**

(when not specified)

</td><td class="align-center" colspan="2" style="width: 29.0533%;">**Range**

</td></tr><tr><td class="align-center" style="width: 13.7242%;">Min

</td><td class="align-center" style="width: 15.3291%;">Max

</td></tr><tr><td style="width: 15.7%;">name</td><td style="width: 8.52993%;">string </td><td style="width: 25.4662%;">User-friendly device name</td><td style="width: 9.5189%;">Yes</td><td style="width: 11.8656%;"></td><td style="width: 13.7242%;">  
</td><td style="width: 15.3291%;"></td></tr><tr><td style="width: 15.7%;">description</td><td style="width: 8.52993%;">string</td><td style="width: 25.4662%;">Description of a device</td><td style="width: 9.5189%;">No</td><td style="width: 11.8656%;"></td><td style="width: 13.7242%;">  
</td><td style="width: 15.3291%;"></td></tr><tr><td style="width: 15.7%;">device\_alias</td><td style="width: 8.52993%;">string</td><td style="width: 25.4662%;">Alphanumeric string to identify a device</td><td style="width: 9.5189%;">Yes</td><td style="width: 11.8656%;">  
</td><td style="width: 13.7242%;">  
</td><td style="width: 15.3291%;">  
</td></tr><tr><td style="width: 15.7%;">enable</td><td style="width: 8.52993%;">boolean</td><td style="width: 25.4662%;">Enabling/disabling a device</td><td style="width: 9.5189%;">No</td><td style="width: 11.8656%;">1</td><td style="width: 13.7242%;">0</td><td style="width: 15.3291%;">1</td></tr><tr><td style="width: 15.7%;">protocol</td><td style="width: 8.52993%;">string</td><td style="width: 25.4662%;">Protocol to be used.</td><td style="width: 9.5189%;">Yes</td><td style="width: 11.8656%;">  
</td><td colspan="2" style="width: 29.0533%;">mbus serial</td></tr><tr><td style="width: 15.7%;">scan\_rate\_ms</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">All reads and writes will be executed within the timeframe in milliseconds.</td><td style="width: 9.5189%;">No</td><td style="width: 11.8656%;">10000</td><td colspan="2" style="width: 29.0533%;"></td></tr><tr><td style="width: 15.7%;">poll\_delay\_ms</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">Minimum time delay in milliseconds to wait  
before sending any data on port.</td><td style="width: 9.5189%;">No</td><td style="width: 11.8656%;">200</td><td colspan="2" style="width: 29.0533%;"></td></tr><tr><td style="width: 15.7%;">timeout\_ms</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">Timeout of waiting for an incoming response in milliseconds</td><td style="width: 9.5189%;">Yes</td><td style="width: 11.8656%;">  
</td><td style="width: 13.7242%;">0</td><td style="width: 15.3291%;">60000</td></tr><tr><td style="width: 15.7%;">address</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">Device address</td><td style="width: 9.5189%;">Yes</td><td style="width: 11.8656%;">  
</td><td style="width: 13.7242%;">  
</td><td style="width: 15.3291%;">  
</td></tr><tr><td style="width: 15.7%;">device</td><td style="width: 8.52993%;">string</td><td style="width: 25.4662%;">Communication port</td><td style="width: 9.5189%;">Yes</td><td style="width: 11.8656%;">  
</td><td style="width: 13.7242%;">PORT1</td><td style="width: 15.3291%;">PORT2</td></tr><tr><td style="width: 15.7%;">baudrate</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">Communication speed, baud/s

</td><td style="width: 9.5189%;">Yes

</td><td style="width: 11.8656%;">9600

</td><td colspan="2" style="width: 29.0533%;">300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200

</td></tr><tr><td style="width: 15.7%;">databits</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">Data bit count for communication

</td><td style="width: 9.5189%;">Yes

</td><td style="width: 11.8656%;">8

</td><td style="width: 13.7242%;">6

</td><td style="width: 15.3291%;">9

</td></tr><tr><td style="width: 15.7%;">stopbits</td><td style="width: 8.52993%;">integer</td><td style="width: 25.4662%;">Stop bit count for communication

</td><td style="width: 9.5189%;">Yes

</td><td style="width: 11.8656%;">1

</td><td style="width: 13.7242%;">1

</td><td style="width: 15.3291%;">2

</td></tr><tr><td style="width: 15.7%;">parity</td><td style="width: 8.52993%;">string

</td><td style="width: 25.4662%;">Communication parity option

</td><td style="width: 9.5189%;">Yes

</td><td style="width: 11.8656%;">none

</td><td colspan="2" style="width: 29.0533%;">none, even, odd

</td></tr></tbody></table>

##### M-Bus parameters for the *Signals* tab

<div class="pointer-container" id="bkmrk-%C2%A0"><div class="pointer anim is-page-editable"><svg class="svg-icon" data-icon="link" role="presentation" viewbox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"></svg><div class="input-group inline block"><input id="bkmrk--0" placeholder="url" readonly="readonly" type="text"></input> <button class="button outline icon" data-clipboard-target="#pointer-url" title="Copy Link" type="button"><svg class="svg-icon" data-icon="copy" role="presentation" viewbox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"></svg></button></div><svg class="svg-icon" data-icon="edit" role="presentation" viewbox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"></svg></div></div><table border="1" id="bkmrk-parameter-type-descr" style="width: 100%; height: 397.6px;"><tbody><tr style="height: 51.3333px;"><td class="align-center" rowspan="2" style="width: 12.7331%; height: 102.667px;">**Parameter**  
  
</td><td class="align-center" rowspan="2" style="width: 8.65355%; height: 102.667px;">**Type**  
  
</td><td class="align-center" rowspan="2" style="width: 42.8969%; height: 102.667px;">**Description**  
  
</td><td class="align-center" rowspan="2" style="width: 9.88977%; height: 102.667px;">**Required  
</td><td class="align-center" rowspan="2" style="width: 14.9588%; height: 102.667px;">**Default value**

(when not specified)

</td><td class="align-center" colspan="2" style="width: 10.8783%; height: 51.3333px;">**Range**

</td></tr><tr style="height: 51.3333px;"><td class="align-center" style="width: 5.5625%; height: 51.3333px;">Min

</td><td class="align-center" style="width: 5.31575%; height: 51.3333px;">Max

</td></tr><tr style="height: 35.4667px;"><td style="width: 12.7331%; height: 35.4667px;">signal\_name</td><td style="width: 8.65355%; height: 35.4667px;">string

</td><td style="width: 42.8969%; height: 35.4667px;">User-­friendly signal name

</td><td style="width: 9.88977%; height: 35.4667px;">Yes</td><td style="width: 14.9588%; height: 35.4667px;">  
</td><td style="width: 5.5625%; height: 35.4667px;"></td><td style="width: 5.31575%; height: 35.4667px;"></td></tr><tr style="height: 35.4667px;"><td style="width: 12.7331%; height: 35.4667px;">device\_alias</td><td style="width: 8.65355%; height: 35.4667px;">string

</td><td style="width: 42.8969%; height: 35.4667px;">Device alias from a Devices tab

</td><td style="width: 9.88977%; height: 35.4667px;">Yes</td><td style="width: 14.9588%; height: 35.4667px;">  
</td><td style="width: 5.5625%; height: 35.4667px;"></td><td style="width: 5.31575%; height: 35.4667px;"></td></tr><tr style="height: 35.4667px;"><td style="width: 12.7331%; height: 35.4667px;">signal\_alias</td><td style="width: 8.65355%; height: 35.4667px;">string

</td><td style="width: 42.8969%; height: 35.4667px;">Unique alphanumeric name of the signal to be used

</td><td style="width: 9.88977%; height: 35.4667px;">Yes</td><td style="width: 14.9588%; height: 35.4667px;">  
</td><td style="width: 5.5625%; height: 35.4667px;"></td><td style="width: 5.31575%; height: 35.4667px;"></td></tr><tr style="height: 35.4667px;"><td style="width: 12.7331%; height: 35.4667px;">enable</td><td style="width: 8.65355%; height: 35.4667px;">boolean

</td><td style="width: 42.8969%; height: 35.4667px;">Enabling/disabling of an individual signal

</td><td style="width: 9.88977%; height: 35.4667px;">No</td><td style="width: 14.9588%; height: 35.4667px;">1</td><td style="width: 5.5625%; height: 35.4667px;">0

</td><td style="width: 5.31575%; height: 35.4667px;">1

</td></tr><tr style="height: 35.4667px;"><td style="width: 12.7331%; height: 35.4667px;">log</td><td style="width: 8.65355%; height: 35.4667px;">integer

</td><td style="width: 42.8969%; height: 35.4667px;">Enable logging in the event log

</td><td style="width: 9.88977%; height: 35.4667px;">No</td><td style="width: 14.9588%; height: 35.4667px;">0</td><td style="width: 5.5625%; height: 35.4667px;"></td><td style="width: 5.31575%; height: 35.4667px;"></td></tr><tr style="height: 29.8667px;"><td style="width: 12.7331%; height: 29.8667px;">number\_type</td><td style="width: 8.65355%; height: 29.8667px;">string</td><td style="width: 42.8969%; height: 29.8667px;">Type of a number (FLOAT, DOUBLE, DIGITAL, etc.)</td><td style="width: 9.88977%; height: 29.8667px;">Yes</td><td style="width: 14.9588%; height: 29.8667px;">  
</td><td style="width: 5.5625%; height: 29.8667px;">  
</td><td style="width: 5.31575%; height: 29.8667px;">  
</td></tr><tr style="height: 57.8667px;"><td style="width: 12.7331%; height: 57.8667px;">job\_todo</td><td style="width: 8.65355%; height: 57.8667px;">string

</td><td style="width: 42.8969%; height: 57.8667px;">Tag job as single or multiple comma-separated OBIS codes

</td><td style="width: 9.88977%; height: 57.8667px;">Yes</td><td style="width: 14.9588%; height: 57.8667px;">  
</td><td style="width: 5.5625%; height: 57.8667px;"></td><td style="width: 5.31575%; height: 57.8667px;"></td></tr><tr style="height: 29.8667px;"><td style="width: 12.7331%; height: 29.8667px;">tag\_job\_todo</td><td style="width: 8.65355%; height: 29.8667px;">string</td><td style="width: 42.8969%; height: 29.8667px;">Tag sub job</td><td style="width: 9.88977%; height: 29.8667px;">Yes</td><td style="width: 14.9588%; height: 29.8667px;">  
</td><td style="width: 5.5625%; height: 29.8667px;">  
</td><td style="width: 5.31575%; height: 29.8667px;">  
</td></tr></tbody></table>

Optional parameters for signals are available on this page -&gt; [Optional parameters for signals](https://wiki.elseta.com/books/manual/page/182-optional-parameters-for-signals).

If you wish to include mathematical expressions in your signals, the guidelines can be found on this page -&gt; [Mathematical functions](https://wiki.elseta.com/books/manual/page/183-mathematical-functions).

### Debugging

If M-Bus does not work properly (e.g. no communication between devices, data is corrupted, etc.), a user can launch a debug session from command-line interface and find out why the link is not functioning properly.

<p class="callout warning">On the web interface's protocol connections page, M-bus devices will not be displayed. If the connection is established correctly, it can be observed on the imported signals page.</p>

To launch a debugging session, a user should stop the *pooler* process and run the *pooler* command with respective flags.

- Step 1: Open the command terminal on your computer.
- Step 2: Connect via SSH, example of the command **ssh root@192.168.1.1** and then enter your designated password.
- Step 3: Service must be stopped by entering the following command into the wcclite:  
    **/etc/init.d/pooler stop**
- Step 4: After service is stopped it must be started with the preferred configuration file (JSON  
    files found in /etc) and a debug level 7: **pooler -c /etc/pooler/pooler.json -­d7**
- Step 5: Once the problem is diagnosed normal operations can be resumed with the following command: **/etc/init.d/pooler start**

##### POOLER command line debugging options

```
-h [ ––help ] Display help information <br></br>-V [ ––version ] Show version<br></br>-d<debug level> Set debugging level <br></br>-c [ ––config ] Config path<br></br>-s [ ––serial ] Show serial port data<br></br>-r [ ––raw ] Show raw telegram data<br></br>-B [ ––mbus ] Show M-Bus driver output
```

One example of debugging involves using the following command -&gt; **pooler -c /etc/pooler/pooler.json -B -d7 -s**.

In this mode, both request packets and received packets are visible, along with the M-Bus driver output showing translated signal values received. This information can be instrumental in determining the correct configuration for the signal sheet. Additionally, messages regarding incorrect M-Bus frames can be observed, aiding in identifying potential wiring mistakes.