Wiren Board 8.5

Wiren Board 8.5 is a DIN-rail industrial automation controller with a 64-bit processor. It runs Debian Linux and combines Ethernet, dual-band Wi-Fi, Bluetooth, USB, RS-485, 1-Wire, universal I/O, optional cellular connectivity and four internal expansion slots in one programmable controller.

Changes from the previous version

Wiren Board 8.5 uses the same processor family and memory as Wiren Board 8.4. The hardware changes are:

• all four MOD1–MOD4 slots have external I/O terminal blocks and accept compatible expansion modules; I2C modules remain limited to MOD3 and MOD4;
• MOD1 and MOD2 now support UART expansion modules in addition to GPIO modules;
• processor-board heating allows start-up and operation at ambient temperatures down to −40 °C;
• one combined USB-C Debug USB connector replaces the separate Debug Network and Debug Console connectors;
• the buzzer is connected to the embedded controller, providing audible feedback during power-up, reboot and button operation;

Compared with Wiren Board 7, the Wiren Board 8 family uses a 64-bit quad-core processor at 1.5 GHz, up to 4 GB RAM and four expansion slots.

• CAN is not fitted in the base configuration; up to four CAN ports can be added with WBE2-I-CAN-ISO v.2 modules;
• Debian Linux 13 Trixie uses 64-bit packages, so custom software compiled for earlier controllers must be checked for compatibility.

Technical specifications

First start

Assembly and startup

Before applying power, install any required internal expansion modules and connect peripheral devices according to their instructions. Mount the controller on a DIN rail and connect its supply. After the operating system has loaded, the indicator flashes green at a steady rate.

Connecting to a computer

Use Debug USB for initial setup and Wi-Fi or Ethernet for normal operation. The debugging function also provides access to bootloader logs and the command line during recovery.

Debug USB

Debug USB provides access to both the web interface and controller console. It works with Windows 7 and later and Linux. It does not work with macOS computers or phones; use Wi-Fi or Ethernet on those devices.

The connection creates a virtual network adapter with a fixed IP address. This adapter becomes available after the controller has finished starting and its indicator flashes green evenly.

The computer's USB port can power the controller without an external supply. USB power is limited: disconnect side modules and devices connected to Vout, +5V and USB.

1. Connect a USB-C cable between the computer and Debug USB. The controller beeps and starts.
2. Wait until the indicator beside the power button flashes green steadily.
3. The computer detects a virtual drive labelled WIRENBOARD. It contains webui.html, a link to the web interface, and README.txt, containing the controller IP address.
4. Open webui.html or enter http://10.200.200.1 in a browser. SSH is available at the same address, 10.200.200.1.

The Debug USB connector also supports firmware updates and erasing all data and settings.

Wi-Fi

The controller initially creates an unprotected access point. Open the list of Wi-Fi networks on your laptop or phone and select WirenBoard-XXXXXXXX, where XXXXXXXX is the controller serial number. The controller is available at 192.168.42.1.

Ethernet

Both Ethernet ports obtain their IP address through DHCP. Use a router with DHCP enabled, as is usual in a home or office network.

1. Connect an RJ-45 patch cable from a free router port to either controller Ethernet port.
2. Find the address assigned to the controller in the router's settings.
3. On a computer connected to the same router, enter that address in a web browser.

Web interface

The preinstalled web interface lets you configure the controller and connected devices, write automation rules, configure notifications and create an operator interface with graphical and text dashboards. See the controller web interface guide.

Command line

Wiren Board runs Linux, so settings are stored in files. Most settings can be changed in the web interface, but the command line is needed for some tasks, including installing additional software and configuring the time zone. Connect by SSH or through the debug port. The default credentials are root / wirenboard.

Security

Incorrect security configuration can cause loss of data or controller access and failure of the automation system. The controller runs many services and is intended to operate within a trusted local network.

The factory configuration exposes the Wi-Fi access point, SSH with default credentials, the web interface and the MQTT broker. Third-party software may open additional ports; check its documentation and configure its authentication.

Unauthorized access to these services can expose or destroy data. For example, MQTT or web-interface access could be used to upload a wb-rules script that adds an attacker's access key or changes your password.

1. Immediately protect the default Wi-Fi access point with a password, or disable it if not needed.
2. Change the SSH password; preferably use SSH key authentication.
3. In corporate networks or VPN-accessible installations, configure web-interface users and access levels and protect the MQTT broker with a password.

For remote access, use Wiren Board Cloud, Tailscale, OpenVPN or an equivalent service. If a public IP address must be assigned directly to the controller, apply these precautions and have a system administrator configure HTTPS, close unnecessary ports and harden the installation.

Next steps

Update the controller firmware; the web interface is the simplest method. Set the correct time zone and configure automation using wb-rules. The testing release is available for active development and commissioning where the latest package versions are needed. If you forget the login password, use the root-password recovery procedure. Diagnose any controller problems before continuing commissioning. If required, erase the data and restore the factory-installed software.

Software

Overview

The controller runs Debian Linux. An official Debian port exists for its processor architecture, so standard Linux applications can be installed with apt install package_name. The controller software is distributed as packages grouped into releases: stable, installed on new controllers, and testing, a rolling release with the latest package versions.

Preinstalled software

MQTT is the backbone of the software architecture: services communicate through a shared MQTT broker. The web interface runs directly on the controller. It lets you monitor and control the controller and connected devices, add devices, change settings, update software, write rules, configure SMS and email notifications, and view historical graphs of values such as temperature and voltage.

The wb-rules rules engine lets you create automation rules such as “if the sensor temperature falls below 18 °C, turn on the heater.” Rules are written in a JavaScript-like language using the web interface. Code-free automation scenarios provide a simpler tool for common tasks such as lighting and heating.

The controller supports peripheral devices through its drivers. Connected Modbus devices can be configured in the web interface, and their firmware can be updated. Controller firmware updates and transferring files between the controller and a computer are separate maintenance operations.

SCADA integration

Available integration mechanisms include a Zabbix agent, Modbus TCP/RTU gateway, OPC UA gateway, IEC 60870-5-104 gateway, SNMP agent and MQTT.

Third-party software

You can additionally install:

• Node-RED for visual programming.
• IEC 61131-3 environments supporting FBD, ST, LD and SFC.
• Grafana for data storage and visualization.
• IntraSCADA for building management, industrial monitoring and automation.
• Rapid SCADA, an open-source industrial automation platform.
• Home Assistant, an open-source home automation platform.
• Docker for running applications in isolated environments.

Additional applications are available from Debian repositories and integration partners.

Developing custom software

You can develop your own controller software or build a firmware image containing the required settings, licences and packages. Install your image using the standard update tools, or arrange factory installation for a separately ordered batch.

The controller software is open source, with examples available in the manufacturer's GitHub repositories. Developer documentation covers firmware partition layouts and FIT-image builds, software development, the ATECCx08 security chip and the MQTT-RPC protocol.

Boot status indicator

Hardware with a separate two-colour LED can display green, red or orange. Hardware with the LED built into the button alternates red and green. The indicator provides a quick boot diagnostic:

Internal and side expansion modules

Four internal slots accept compact expansion boards for RS-485, RS-232, relay outputs, HDMI and other functions. All four slots expose I/O terminal blocks. MOD1 and MOD2 support GPIO and UART modules; I2C expansion modules are installed in MOD3 or MOD4.

Wireless interfaces

Dual-band 2.4/5 GHz Wi-Fi can operate as an access point, a client, or both simultaneously. Bluetooth 4.2 Low Energy can detect nearby phones or beacons.

Z-Wave and Zigbee support can be added with compatible radio modules. Cellular modules provide 2G, 3G or 4G LTE, SMS and Internet access; two SIM slots are multiplexed so only one SIM is registered at a time. Connect Wi-Fi, cellular and radio antennas to their SMA connectors. If cellular reception is weak, use a remote antenna positioned away from the controller.

Wired interfaces

The two 10/100 Ethernet ports use DHCP by default. The USB-A connector is a USB 2.0 host and can also be used for firmware installation.

Two RS-485 ports are built in; up to four additional isolated RS-485 or CAN ports can be installed with expansion modules. HDMI output is available through an internal expansion module.wb-mqtt-serial driver connects RS-485 devices to MQTT.

Debug USB is the recovery interface for bootloader messages, shell access and the web interface. It remains available if normal network configuration is unavailable.

MicroSD storage

The high-speed MicroSD slot is on the left side. Insert the card contacts-down until it clicks. It can store backups and logs or extend available data storage. The card appears as /dev/mmcblk1; its first partition is mounted automatically at /mnt/sdcard.

Universal I/O A1–A4

Each channel has a 100 kΩ input resistance. Digital and analogue input measurements operate simultaneously while the output switch is off. Setting Ax_OUT on connects the terminal to GND through the open-collector output.

W1–W2 channels

W1 and W2 are independently configurable as 1-Wire interfaces or dry-contact digital inputs. Select the mode in the web interface under Settings → Configs → Expansion modules and ports → Wx terminal mode.

In 1-Wire mode an internal 3 kΩ pull-up is already fitted, so no external resistor is required. Supported temperature sensors include DS18B20. Bus length, topology and cable quality determine the reliable number of sensors. In digital-input mode, the channel activates when shorted to GND.

5Vout and Vout power outputs

5Vout supplies 5 V for sensors and is protected against short circuit and external overvoltage. It remains active on backup power and can be switched from the 5V_OUT channel of the Discrete I/O device.

The two Vout terminals carry controller supply voltage with a combined 1 A limit. Their software state is retained across restart and power-button shutdown. Vout switches off automatically above a 29 V controller supply; on backup power it provides 11 V. Control it with Relays & FETs → V_OUT. A self-resetting 1 A polyfuse protects the output.

RS-485 termination and failsafe bias

An RS-485 line must be terminated with 100–120 Ω at both physical ends. The controller has software-controlled terminators. Failsafe bias resistors on A and B are enabled by default; disable them in the web interface when the controller operates as an RS-485 slave.

Terminal blocks and wiring

Use flexible stranded conductors with insulated wire-end ferrules. For control terminals use 0.35–1 mm² single ferrules or 0.35–0.5 mm² twin ferrules; torque is 0.2 N·m. Power terminals accept up to 2.5 mm² single or 1.5 mm² twin ferrules; torque is 0.5 N·m. The recommended ferrule sleeve length is 8 mm. Do not overtighten the removable 3.5 mm-pitch screw terminals.

The software-controlled buzzer is connected to the embedded controller. It provides audible feedback during power-up, reboot and button operation; its frequency is configurable.

Power and backup power

Connect one or two 9–48 V DC power supplies to V+ with common GND. Optional active or passive PoE can power the controller through Ethernet 1. When several sources are connected, the source with the highest voltage is used.

A WBMZ6-BATTERY module provides backup power. When Vin falls below the configured threshold the controller switches to the battery and can remain running or perform an orderly shutdown.

Embedded controller, scheduled wake-up and watchdog

The embedded microcontroller manages power, the real-time clock, A1–A4 voltage measurement, board temperature, scheduled wake-up and the watchdog timer.

To shut down now and wake after 60 seconds:

rtcwake -m off -s 60

To wake at an absolute local time, convert it to Unix time and pass the result to rtcwake:

date +%s -d "2026-10-09 07:15"
rtcwake -m off -l -t 1791522900

Verify the generated timestamp for the controller time zone before using it. Scheduled wake-up can also be automated through wb-rules.

The hardware watchdog reboots the controller if monitored software stops responding. Stop the watchdog before changing configuration of monitored services, validate the changes, then start it again. If an invalid configuration causes a reboot loop, connect over SSH during the first 60 seconds after boot and stop the watchdog service.

Processor-board heating

At power-up, the embedded controller measures board temperature. Below −15 °C it enables the heater. Below −20 °C it delays processor-board power until the board warms to −15 °C, then continues heating until −10 °C. Heating operates only from V+ or PoE, not from Debug USB or the backup battery.

Remote operation and troubleshooting

For remote sites, use a managed remote-access service, Tailscale or a properly administered VPN. Keep date, time and time zone correct for logs, certificates and scheduled rules. The hardware batch number is printed on the enclosure label and PCB and combines the baseboard and processor-board batch numbers.

Relays and contactors can generate high-frequency transients of several kilovolts, especially with inductive loads. Fit the appropriate RC snubber, varistor or other suppression device directly at the load or switching element, route power and communication wiring separately, and use correct RS-485 topology and termination.

Board and dimensions

Other interfaces

The buzzer produces an audible signal with an adjustable frequency.

Supported devices

The controller supports Wiren Board RS-485 devices and other peripheral devices through the available interfaces, drivers and integration protocols. See the device manuals and supported-device compatibility information for the required connection and configuration procedure.

Network configuration for remote sites

Options include Wiren Board Cloud for remote administration and Tailscale for remote access without running your own VPN server. Configure and verify the site's network settings before leaving the controller unattended.

Date, time and time zone

Configure the controller's date, time and local time zone. Time synchronization settings are available through the NTP configuration editor under Settings → Configs. See the time synchronization instructions.

Known issues

Check the hardware errata for Wiren Board 8 when diagnosing an issue that may depend on the controller revision.

Hardware revisions

The batch number (Batch №) is printed on the label on the side of the enclosure and on the printed circuit board. The controller's batch number combines the batch numbers of its base board and processor board. Hardware revision records describe changes to the controller boards.

Troubleshooting

Interference from relays and contactors

Relays and contactors can produce interference that affects nearby devices. When switching a load, particularly an inductive one, the contacts generate high-frequency transients that can reach several kilovolts and couple into other circuits. Snubber networks suppress these transients, reducing interference and improving equipment stability.

Additional information

• Wiren Board 8.5 peripherals: low-level access to GPIO and other controller peripherals from custom software.
• Direct GPIO access.
• Firmware updates and factory reset.
• Recovering the root password.

Images and drawings

• CorelDRAW 2018 library, using the Ubuntu font: WB-Library.cdr.zip.
• Visio library of Wiren Board devices: WB-Visio-Lib.zip. Additional enclosure, circuit-breaker and contactor symbols are available from third-party libraries.
• SVG library: WB-Library.svg.zip.
• AutoCAD 2013 DXF drawing: Wiren_Board-8.5.dxf.zip.
• PDF drawing: Wiren_Board-8.5.dxf.pdf.
• AutoCAD Electrical symbol library: Wirenboard-AE-base.zip.