Wiren Board Сompact RS-485, Modbus RTU Relay module / 6 relay WB-MR6CU v.2

Compact module with 6 relay outputs, no inputs and control via RS-485. Each channel can withstand continuous currents of up to 16 A and inrush currents of up to 80 A. The compact DIN rail housing occupies only 2 modules.

Used for direct control of lighting, curtain drives and other loads rated up to 10 A (2 kW) in residential, office and industrial premises.

Main characteristics

Advantages

• Powerful relays that can withstand high inrush currents.
• Indication of the output status on the housing for quick diagnostics and determination of the output status during commissioning.
• Safe mode in case of RS-485 communication failure.
• Compact housing for DIN rail, 2 modules.
• Fast and easy integration into automation and monitoring systems.

Supports Fast Modbus ⚡, which allows relay channel states to be instantly delivered to the Wiren Board controller.

Hardware

Specifications:

• 6 relay channels rated 10 A 230 V AC.
• Maximum continuous current: 16 A per channel.
• Maximum starting current: up to 80 A (20 ms).
• The outputs are combined into two groups of 3 relays each, each group can switch a total of no more than 20 A.
• No entrances.

• Supply voltage: 9…28 V direct current.
• Interface: RS-485, Modbus RTU.
• Operating temperature: -40…+80 °C.
• DIN rail housing, 2 modules.

Hongfa Long Life Relays

Reliable Hongfa relays are used for switching. The relays have silver tin dioxide (AgSnO) contacts, which ensures operation with high inrush currents up to 80 A (20 ms). Therefore, the WB-MR6CU v.2 moduleFineSuitable for controlling LED lamps.

To ensure the quality of the relay we tested them with high inrush current several times higher than nominal.

The relay manufacturer claims a service life of at least 100 000 operations.

Safe mode

If the module is installed at a distance from the switchboard and connected to the RS-485 bus, then there is a risk of loss of control from the head unit. In order not to lose control over an important technological process, the module has a safe mode that allows you to switch the relay outputs to a specified state.

For each output, you can configure its own safe state and the need to switch to it in case of loss of communication. In addition, you can enable or disable control from inputs in safe mode, for example, prohibit control from buttons when communication with the device is lost.

Curtains controlling

The WB-MR6CU v.2 module has a special mode for working with curtains, which eliminates the simultaneous activation of the direction relay and guarantees a pause between switchings. In the settings, you can set the opening/closing time, pause time when changing direction, as well as actions when turning on the power and entering safe mode.

The outputs are individually configurable, so only part of the outputs can be used to control curtains, and the rest can be used for other purposes. You can also configure the curtain action for each of the 4 types of button presses connected to the module inputs.

Fast Modbus support

All Wiren Board devices, in addition to the standard Modbus RTU, can work with its extension Fast Modbus ⚡, which adds new features:

• instant polling of input states and measured values via events;
• quick search for devices connected to the controller;
• resolving address collisions on the bus.

Additional features are enabled automatically - if the device supports extension, the controller driver will work with the device quickly Modbus if the device does not know anything about the extension - it will work using standard Modbus RTU.

Quality control at every stage production

We develop and manufacture all Wiren Board devices ourselves. All devices undergo multi-stage quality control:

• During development — checking the components used for compliance with the declared characteristics and testing the prototype device at extreme operating conditions.
• After installing SMD components — automated optical inspection.
• After soldering the lead components — visual inspection of soldering.
• After assembling the device — functional testing on an automated stand.
• When shipped to the warehouse — control of completeness, stickers, appearance.

Thanks to this approach, the failure rate is no more than 0.5% of all released devices. Read more in the article About device reliability.

If the device fails within two years from the date of purchase, we will replace it for free without the need to send it to a service center.

Setup

When used with a Wiren Board controller, you can use the mouse in the web interface:

• enable and disable channels and configure the polling period,
• set the state of the outputs when power is applied,
• configure safe mode settings,
• switch the outputs to the curtain drive control mode.

When used with other equipment, the module can be configured via the RS-485 bus by writing values to Modbus registers. The register table is open, well documented and available online in the device documentation.

Reading the readings

If a Wiren Board controller is used, the output states available in the controller's web interface and can be used in automation scripts or transferred to a higher-level system. The device card displays only the channels enabled in the survey settings.

The module also transmits all data via Modbus RTU (RS-485), which can be read by any equipment or software that supports this protocol: third-party controllers, HMI panels or SCADA.