M-Bus to LoRaWAN or NB-IoT finds its application mainly in the reading of electricity meters and calorimeters. The M-Bus converter supports connections of up to 5 UL (Unit Loads) and communication is based on the EN 137 57-3 protocol.
The converter is available in several variants with a D, or 2xD battery for long life even in the most demanding applications.
Thanks to the LUA scripting interface the logic of the device can be modified to fit your needs - be it a data parsing based on the specific VIF and DIF value, as a transparent M-Bus bridge, or as a general IoT device that sends an M-Bus data to the server without any modifications.
To get a better understanding of the LUA scripting interface, you can visit the general application note here
¶ Technical specification
| M-Bus interface | |
| Device type: | Master |
| Communication speed: | 300 - 9600 Bd |
| Maximum connected devices: | 5 UL |
| M-Bus protocol: | EN 137 57-3 |
| LoRaWAN | |
| LoRaWAN specification: | 1.0.3 |
| Registration method: | OTAA, ABP |
| Class: | A, C |
| Frequency: | 868 MHz (ISM) |
| TX Power: | 12.7 dBm |
| Antenna: | External |
| FUOTA | Yes |
| NB-IoT | |
| Bands: | B1, B3, B5, B8, B20, B28 |
| NB module: | SIM 7020E |
| Supported protocols: | TCP/UDP |
| Antenna: | External |
| TX Power: | 23 dBm |
| Configuration: | With cable over GUI or remotely (over the air) |
| General information | |
| IP coverage: | IP65 |
| Dimensions: | 145 x 90 x 55 mm |
| Operational temperature: | -30 to +60 °C |
| Weight: | 250 g |
| HS code: | 85269200 |
| Single battery power supply | |
| Battery type: | Lithium |
| Battery capacity: | 14 000 mAh |
| Voltage: | 3.6 V |
| Rechargeable: | No |
| Replaceable: | Yes |
| Double battery power supply | |
| Battery capacity: | 28 000 mAh |
| External power supply - 220V AC | |
| Voltage: | 85 - 305 V |
| Frequency: | 47-63 Hz |
| Maximum consumption: | 4 W |
¶ Ordering codes
| Code | Description |
| ACR-CV-101N-M-D2 | M-Bus to NB-IoT converter with 2 x D battery |
| ACR-CV-101L-M-D2 | M-Bus to LoRa converter with 2 x D battery |
| ACR-CV-101N-M-D | M-Bus to NB-IoT converter with D battery |
| ACR-CV-101L-M-D | M-Bus to LoRa converter with D battery |
| ACR-CV-101L-M-EAC | M-Bus to LoRa converter with AC external power supply |
| ACR-CV-101N-M-EAC | M-Bus to NB-IoT converter with AC external power supply |
¶ The installation proccess
¶ Battery-powered version
- Unscrew the 4 screws holding the cover and remove the cover.
- Remove the battery and run the communication interface wires through the PG bushing.
- Screw on the LoRaWAN antenna and connect the communication interface wires to the terminal board.
- Insert the battery and connect the battery connector to the power connector on the converter board.
- Replace the device cover and tighten the 4 screws holding the cover. Make sure that the PG bushing is tightened.
- Secure the device at the installation site with screws or cable ties.
- Register the device to the LoRaWAN network using the registration keys.
¶ Externally-powered version
- Unscrew the 4 screws holding the cover and remove the cover.
- Run the communication interface wires through one of the PG bushings and the power wires through the other bushing.
- Screw on the LoRaWAN antenna and connect the communication interface wires to the terminal board.
- Connect the power lines to the terminal board.
- Replace the device cover and tighten the 4 screws holding the cover. Make sure that the PG bushing is tightened.
- Secure the device at the installation site with screws or cable ties.
- Register the device to the LoRaWAN network using the registration keys.
¶ Recommendations for the best function
The universal converter is designed for both indoor and outdoor use. For outdoor installation, place the converter with the antennas pointing down.
Always tighten the PG bushing gently, without the use of tools. It is not necessary to use silicone or other adhesives for the proper water tightness of the device.
Remote configuration of the converter is possible using tools provided by ACRIOS Systems s.r.o. Contact us at info@acrios.com to be provided with needed configuration tools.
When handling the device without the lid on, it is essential to avoid contact with liquids. Never place the device on conductive pads, and do not touch the components on the device unnecessarily.
For the correct functioning of the device, it is necessary to have sufficient coverage of the LoRaWAN or NB-IoT network at the installation site.
¶ Configuration proccess
The configuration can be done either remotely, or via GUI and the configuration cable. Remote configuration requires a modified LUA script and this option is being used during the installation of tens and hundreds of units. For the proof of concept, the local configuration by GUI is being used. For special applications, we can provide you with a backend tool as well.
The example of remote configuration over the air can be seen in the application note here.
The backend solution can be seen here.
¶ Local configuration proccess
Please, do download our GUI - older version - here. For the connection, the ACR-CONFIG configuration cable will be needed as well. The start-up process of the converter consists of 2 main parts. The first is the bootloader part. The bootloader is responsible for the correct launch of the application firmware and also the bootloader allows us the remote firmware update. The bootloader is running for 1 to 3 minutes depending on its ability to join the NB-IoT or LoRaWAN network. During this bootloader process, you can not connect to the GUI. To skip a bootloader, you can press and hold the button until the LED lights up.
¶ Connecting to the GUI and configuration
- Insert the 3.5mm jack of the ACR-CONFIG cable into the 3.5mm jack receptacle on the board
- Launch the GUI
- Click “Connect”
- Power-on the converter
- The blue LED will glow. This is a sign of a bootloader.
- Press and hold the button until you skip the bootloader and GUI will start connecting
- Configure the necessary parameters of the converter within a “Configuration” section of the LUA script
- After you are done, press “Disconnect”
- Repeat the power cycle