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USB ↔ M-Bus Converter
1 - USB M-Bus Master for 20 Loads
These informations are provided “AS IS” and without any warranty of any kind.
This module provides a very convenient way to operate a Wired M-Bus via USB. It takes the role of the M-Bus Master.
Unlike most other M-Bus converters that expect TTL or RS485 inputs, it already comes with an USB-Serial converter built-in.
And while the CH340 might not be one of the best performing ICs, it certainly gets the job done for wired M-Bus communication, which usually ranges from 300 to 9600 bits/s.
Pros
- 20 M-Bus loads (~1.8 W) is pretty much the maximum that one can power from an USB port, considering DC-DC conversion inefficiencies
- PCB and components seem to be pretty good quality, works flawlessly
- USB Type B Socket, Plug-in Screw Terminals and its compact board design make it a perfect choice for DIN Rail mounting
- Decent price-performance ratio
Cons
- Markings have been removed/lasered from most ICs, making it impossible to identify individual components
- Barely possible to find any official information about this module
General Overview / Specs
| Model | USB To M-Bus Master (6832-chong ???) |
| Manufacturer | UNKNOWN (Dykbcells / DYKBmetered ???) |
| Made in | Mainland China |
| Power Supply Voltage | 5 V (USB) |
| Max. USB Current | 500 mA |
| Max. USB Idle Current | 25 mA |
| USB Connector | USB 2.0 Type B Socket |
| USB Serial Vendor | 1a86 QinHeng Electronics |
| USB Serial Product | 7523 CH340 Serial Converter |
| Max. communication speed | 300–115200 bps auto-adaptive |
| M-Bus Connector | Plug-in Screw Terminal 5.08 mm |
| M-Bus Voltage | 36 V (idle) / 24 V (transmission) |
| Max. M-Bus Loads | 20 w/ 1.5 mA each |
| Max. M-Bus Current | 50 mA (20 * 1.5 mA + 18.5 mA = 48.5 mA) |
| Protections | Over-Voltage/-Current, Short-Circuit, ESD |
| LED Indicators | Power, TX, RX |
| Dimensions | 84.5 × 45.0 × 25.5 mm |
| Operating Temperature | -25°C to +70°C |
Availability / Order
AliExpress
- https://s.click.aliexpress.com/e/_c4TbqY4T
- https://s.click.aliexpress.com/e/_c36KFwyb
- https://s.click.aliexpress.com/e/_c3R8WBqL
- https://s.click.aliexpress.com/e/_c2ux8OIP
Case / Mounting / DIN-Rail
3D Printed Case
I’ve designed a DIN-Rail mountable case for this board, it is available on eBay.de
As most of my cases for electronic devices, it has been printed using insulating and flame-retardant (UL 94 HB) DuraPro ABS filament from Extrudr.
Specifications: DR-Case-USB-B-MBUS20.specs.pdf
STL Files for 3D Printing
The .stl files for the DIN-Rail case will soon become available on Cults3D.com