WB-MGU Interface Converter with WBE2 modules (RS-485, Ethernet, Wi-Fi)
Purpose
Designed for connecting devices with an RS-485 interface to an automation server via Ethernet or Wi-Fi. The server can be any controller / computer supporting the required protocols.
The device has one RS-485 (Modbus RTU) port and one slot for WBE2 extension modules. Examples of those modules include wired interfaces like isolated RS-485, CAN, KNX, OpenTherm and so on, or wireless interfaces like Z-Wave LR, Zigbee or Matter. Extension modules are communicating with the main ESP32 MCU via UART.
Two modes are available for the RS-485 port:
- Modbus TCP — for Modbus devices only;
- transparent gateway — suitable for any protocols running over RS-485.
The device is flashed and ready to use as a gateway, but you can write your own firmware for it and use it for other tasks. Read more about developing DIY firmware.
Technical specifications
| Parameter | Value |
|---|---|
| General | |
| Main MCU | ESP32 |
| CPU Core | Xtensa® dual-core 32-bit LX6 @ 240 MHz |
| Flash | 4 MByte |
| SRAM | 520 KByte |
| PSRAM | 0 MByte (default), 8 MByte (option) |
| Power supply | |
| Interface power supply voltage | 9 V — 28 V DC |
| Power consumption at 24 V | 1 W |
| Maximum current from Vout | 2.5 A |
| Maximum current from Vout when powered by PoE (continuous) | 500 mA |
| Power inputs |
|
| Power input priority |
from the input with higher voltage |
| Output for powering external devices | |
| Vout | Module power supply voltage is supplied to the terminals, with overcurrent protection above 2.5A, capable of being disabled via software.
When powered by PoE, a stabilized 24 V voltage will be supplied to Vout. When powered by PoE, the current drawn from Vout is lower. |
| Клеммники и сечение проводов | |
| Рекомендуемое сечение провода с НШВИ | 0.35 – 1 мм2 — одинарные, 0.35 – 0.5 мм2 – сдвоенное обжатие |
| Длина стандартной втулки НШВИ | 8 мм |
| Момент затяжки винтов | 0.2 Н∙м |
| Communication | |
| Data exchange protocol |
Via RS-485 terminals:
|
| Interfaces |
|
| Operating conditions | |
| Air temperature | |
| Relative humidity | Up to 95%, non-condensing |
| Climatic execution according to GOST 15150-69 | O2.1* |
| Warranty period | 2 years |
| Service life | 5 years |
| Габариты | |
| Ширина, DIN-юнитов | 2 |
| Габаритные размеры (Д x Ш x В) | 36 x 90 x 58 мм |
| Weight (with packaging) |
105 g |
General operating principle
Hardware
The module is based on the ESP32 chip, which implements the functions of an RS-485 gateway, allows controlling peripherals and indicators, and provides a web interface and API for configuring the module.
Network interfaces and packet handling
The module has two network interfaces: Ethernet and Wi-Fi, which can act as an access point or client.
The module's firmware receives packets via Ethernet / Wi-Fi and sends them to the RS-485 port or to the WBE2 extension module port, then translates device responses back. The port selection depends on which TCP port the packet arrived at, default: 502 — RS485-1, 503 — RS485-2.
Power supply
The module can be powered in two ways: directly from the Vin terminal or, optionally, via IEEE 802.3af / 802.3at standard PoE.
Powering via PoE requires a separate WBP-ACTIVE-POE module with a built-in voltage converter, which is installed inside the device. It converts the input PoE voltage to 24 V and supplies it to the gateway's internal power bus.
Using the WBP-PASSIVE-POE module is permitted, but only with a power supply voltage not exceeding 24 V DC. Exceeding this voltage will result in the gateway failure.
The module is equipped with one power output (Vout) for connecting peripheral devices.
| Connected load power | Vin (24 V) | Active PoE mode | Passive PoE mode | |
|---|---|---|---|---|
| 802.3af | 802.3at | |||
| Nominal | 60 W | 15 W | ||
| Maximum short-term | 120 W | 12 W | 28 W | 30 W |
Indication
On the front panel under the sticker, there are indicators showing the status of the module and its outputs.
| Designation | Color | State | Meaning |
|---|---|---|---|
| Status | Green | blinking | the device has booted up and is operating in normal mode |
| solid | power is present, firmware problem | ||
| Vout | Orange | solid | device power ON |
| OFF | device power OFF | ||
| Ethernet | Green | solid | link established |
| blinking | data exchange | ||
| OFF | no link | ||
| Wi-Fi | Green | solid | enabled, no data exchange |
| blinking | data exchange | ||
| OFF | disabled | ||
| RS485 1/2 | Green (RX) | blinking | receiving data from port |
| Orange (TX) | blinking | sending data to port |
Installation
WB-MGU is mounted on a standard 35 mm DIN rail and occupies a width of 2 DIN modules.
Wiring
Module power supply
The V+ GND terminal block with a 5.08 mm pitch is used for power connection.
The module can also be powered by Ethernet PoE.
Network interfaces
The module is connected to the Wiren Board controller or another device directly via Ethernet or via Wi-Fi, including through a router or VPN. The main condition is that the module's IP address must be accessible from the controller.
RS-485
The V+ GND A B terminal block with a 3.5 mm pitch is used to connect devices via the RS-485 bus. Power for the connected devices can also be taken from these terminals. For stable communication with the device, it is important to correctly organize the connection to the RS-485 bus; read about this in the article RS-485 Bus Physical Connection.
For the RS-485 interface, settings for speed, stop bits, and other parameters are available. By default, the terminating resistor and failsafe bias are enabled. They can be disabled in the settings. The RS-485 ground in the WB-MGU is not isolated from the power ground.
Configuration
Web interface
For convenience of settings, the module has a web interface that works in modern browsers on computers and mobile phones. To access it, you need to connect the computer and the module to the same network via one of the interfaces:
- Wi-Fi, where it brings up an access point and automatically distributes IP addresses to clients.
- Ethernet, where IP addresses are not configured; the module must receive them via DHCP, for example, from your router.
Default values are given in the table below. More information about network settings is output to the debug console accessible via the USB-C port under the module cover.
- Web interface screenshots
| General | |
|---|---|
| Login | admin |
| Password | admin |
| mDNS hostname | wb-mge-XXXXXX.local, XXXXXX — last 3 digits of Ethernet MAC in hex format
You can also take the access point name printed on the sticker and add .local to it |
| Wi-Fi | |
| Access point | WB-MGE-XXXXXX, XXXXXX — last 3 digits of Ethernet MAC in hex format. |
| Key (password) | printed on the sticker on the side of the device. |
| IP address | 192.168.5.1 |
| Subnet mask | 255.255.255.0 |
| Ethernet | |
| IP address | DHCP |
| Subnet mask | DHCP |
Web interface access
Access to the module's web interface via Wi-Fi access point
By default, Wi-Fi operates in access point mode:
- Open the list of Wi-Fi access points on your laptop or phone and connect to WB-MGE-XXXXXX, where XXXXXX are the last 3 digits of the Ethernet MAC in hex format.
- Enter the security key (password) printed on the sticker on the side of the device.
- The web interface will be available at 192.168.5.1, login / password — admin / admin.
Access to the module's web interface via Ethernet
By default, the module's Ethernet port is configured to obtain an IP address via DHCP, so you will need a router with configured IP address distribution — usually any router in an apartment or office:
- Connect the module to the router via Ethernet;
- Go to your router's settings and see what IP address it assigned to the module.
- Open a web browser on a computer connected to the same router. The web interface will be available at the IP address from the previous step, login / password — admin / admin.
Access to the module's web interface via Wiren Board Cloud
If the WB-MGU is connected to one of the controller's network interfaces, and the controller is in the Wiren Board Cloud, you can configure proxying for the module's web interface and access it via the cloud. Details in Gaining access to arbitrary web interfaces on the controller.
Saving and loading configuration
Configured parameters can be saved to a file and used to restore them on a new device or when creating identical installations.
All web interface, port, and network interface settings are exported to the file.
Terminator and failsafe bias
The module has installed and enabled by default:
- terminator — a 120 Ohm resistor connected between lines A and B. It should be enabled if the module is at the end of the bus, and disabled if in the middle.
- failsafe bias — 560 Ohm resistors that pull the bus, eliminating uncertainty when device transmitters are turned off. If the module acts as a master, it must be enabled; otherwise, disabled.
The control is software-based; go to the settings of the required port and set the status.
«Modbus TCP» mode
In this mode, the module receives Modbus TCP packets via network interfaces, unpacks them, and sends them to one of the RS-485 ports. Then it packs the received response and sends it back to the network interface to the client that requested the data.
Mode selection is available for each port separately:
- Go to Settings → RS-485 1 (or 2).
- Select Modbus TCP mode.
- If necessary, specify the TCP port from which requests will be forwarded to this RS485 port.
In Modbus TCP mode, the module can only act as a server. Currently, only one simultaneous connection is supported per port.
«Transparent gateway» mode
In this mode, the module receives packets of any protocol (e.g., Modbus over TCP) via network interfaces, unpacks them, and sends them to one of the RS-485 ports. Then it packs the received response and sends it back to the network interface from which the request was received.
Mode selection is available for each port separately:
- Go to Settings → RS-485 1 (or 2).
- Select Transparent mode and choose a role.
- If necessary, specify the TCP port from which requests will be forwarded to this RS485 port.
The following roles are available in «Transparent gateway» mode:
- Server — used when connected to, for example, a Wiren Board controller.
- Client — used when the WB-MGU is connected to another similar module.
In this mode, only one master can poll devices on each port.
If you want to forward two segments of the RS-485 bus over a local network or VPN using a WB-MGU, select the «Server» mode for one module and «Client» for the other, specifying the server's IP address.
When combining two RS-485 bus segments using WB-MGU v.3 gateways and polling devices from a Wiren Board controller, set the timeout in the port settings of the wb-mqtt-serial driver to at least 200-250 ms when working over Ethernet or at least 350 ms when working over Wi-Fi or a VPN.
Configuration in Wiren Board controller
The controller and the module are connected to the same network via a router and obtain IP addresses via DHCP
Connection diagram
WB-MGU module settings, obtained IP address 192.168.0.196
Port settings in wb-mqtt-serial
The controller is connected to the module via Ethernet, the controller is — IPv4 Shared to other computers, the module is — DHCP Client
Connection diagram
Ethernet 2 port configuration on the controller
WB-MGU module settings, obtained IP address 10.42.0.176
Port settings in wb-mqtt-serial
The controller is connected to the module via Ethernet, the controller has — IPv4 Static IP address, the module has — Static IP address
Connection diagram
Ethernet 2 port configuration on the controller
WB-MGU module settings, Static IP address 192.168.1.7
Port settings in wb-mqtt-serial
To manage Modbus devices connected to the module from the Wiren Board controller, you need to configure the wb-mqtt-serial driver:
- Add TCP ports in the wb-mqtt-serial driver settings to receive data from RS-485-1 and RS-485-2 of the module.
- To make the devices appear on the Devices tab in the Wiren Board controller's web interface, add them automatically via Wiren Board devices search on the RS-485 bus, or manually, by selecting a template.
- WBIO modules are added manually, by selecting a template. The module address depends on what the WB-MGE v.3 is used with:
- Wiren Board controller —
<WB-MIO Modbus address>:<WBIO module sequence number (starting from 1)>. - Third-party controller or software — addresses are calculated according to the WB-MIO registers table.
- Wiren Board controller —
Z-Wave Support
WB-MGU can be equipped with the WBE2R-R-ZWAVE-TR extension module to provide Z-Wave LR support. Additionally, TRIDENT IoT ZWay Controller SDK can run on main ESP32 MCU. Choose WB-MGU with 8MB PSRAM option for this.
| Parameter | Value |
|---|---|
| Antenna connector | RP-SMA |
| Z-Wave IC | Trident T32CZ20 |
| Output power | 20dB |
| Supported protocols | Z-Wave, Z-Wave Long Range |
| Supported roles | Z-Wave Controller, Z-Wave End Device |
Device flashing
Flashing connector and debug console
The module is based on the ESP32 chip, and a USB-C programming connector is installed on the board.
To access the USB-C connector, remove the top cover of the device by prying it from the side with something thin. You can also receive debug information from the module through this connector. When connecting the module to a computer via USB, it will be detected as an ACM device that can be opened in any terminal program.
Important: when using the debug console, first connect the USB-C cable to the computer and WB-MGU, and then supply power to the gateway. This will help avoid device reboots, see ERRWB-MGEv30001 for more details.
Writing firmware
For flashing, you can use the esptool utility or an analog. A USB-UART converter based on CH343 is built into the device.
You can check the connection by requesting the chip ID, for example:
$ esptool.py -p /dev/ttyACM0 -b 115200 chip_id
esptool.py v4.8.1
Serial port /dev/ttyACM0
Connecting......
Detecting chip type... Unsupported detection protocol, switching and trying again...
Connecting.....
Detecting chip type... ESP32
Chip is ESP32-U4WDH (revision v3.1)
Features: WiFi, BT, Dual Core, 240MHz, Embedded Flash, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 2c:bc:bb:31:8b:00
Uploading stub...
Running stub...
Stub running...
Warning: ESP32 has no Chip ID. Reading MAC instead.
MAC: 2c:bc:bb:31:8b:00
Hard resetting via RTS pin...
GPIO and interfaces
Below are tables with the connection of interface modules and the addresses of the expander outputs.
| ESP32 | GPIO18 | GPIO23 | GPIO0 | GPIO5 | GPIO19 | GPIO22 | GPIO21 | GPIO25 | GPIO26 | GPIO27 |
|---|---|---|---|---|---|---|---|---|---|---|
| RTL8201FI | MDIO | MDC | CLK | RST | TXD0 | TXD1 | TXEN | RXD0 | RXD1 | CRS_DV |
| TCA9535 | SDA | SCL | PD00 | PD02 | PD04 | PD05 | PD06 | PD07 |
|---|---|---|---|---|---|---|---|---|
| ESP32 | GPIO32 | GPIO33 | ||||||
| RS485 | terminator ON | bias ON | ||||||
| VOut and LED VOut | ON | |||||||
| LED Wi-Fi | OFF | |||||||
| LED Eth | OFF | |||||||
| Status | ON |
In the table above, ON means that applying a logical one to the port turns on this or that node. For the Status LED, if the port is in the HiZ state, the LED will be turned on. TCA9535 has a standard address of 0x20 on the bus.
| PSRAM64H | CE | CLK | SIO0 | SIO1 | SIO2 | SIO3 |
|---|---|---|---|---|---|---|
| ESP32 | GPIO9 | GPIO6 | GPIO8 | GPIO17 | GPIO7 | GPIO11 |
| ESP32 | GPIO14 | GPIO12 | GPIO15 |
|---|---|---|---|
| RS485 | TX | RX | RTS |
| ESP32 | GPIO10 | GPIO4 | GPIO13 |
|---|---|---|---|
| WBE2 | TX | RX | RTS |
In these cases, for ESP32, RX is an input and TX is an output.
| ESP32 | GPIO34 |
|---|---|
| Config (B1) | + |
In this case, when the button is pressed, it applies a logical zero to the ESP32 port.
Images and drawings
Corel Draw 2018 (font — Ubuntu): Файл:WB-Library.cdr.zip
Visio:
- Wiren Board devices: Файл:WB-Visio-Lib.zip.
- Panels, circuit breakers, contactors, and more by a third-party developer.
Module dimensional drawing (DXF): Файл:WB-MGEv3.dxf.zip
Module dimensional drawing (PDF): Файл:WB-MGEv3.pdf
База УГО для AutoCAD Electrical: Файл:Wirenboard-AE-base.zip
WB-MGU PCB with Z-Wave module installed
Overall dimensions
