WB-MAO4

This page describes the latest hardware revision with the latest stable firmware. If your device runs older firmware, update it where possible (see Firmware update).

• hardware revision history;
• firmware changes.

Purpose

The 4-channel analog output module controls devices using 0–10 V signals or PWM signals with a 10 V pulse amplitude, such as servo drives, air damper actuators and valve actuators. The module is controlled by a controller or PC over RS-485 using Modbus commands.

Technical specifications

Operating principle

The device has two output control modes:

• analog 0–10 V: voltage is specified in millivolts (0…10 000);
• pulse-width modulation (PWM) with a 10 V pulse amplitude and variable duty cycle, specified as % × 100 (0…10 000):
  • for a 1 % PWM duty cycle, the value is 100;
  • for a 20 % PWM duty cycle, the value is 2000.

Indicators

The module has an indicator that shows its status without connecting to a controller:

• S (green) — Modbus communication status: lights up when low-voltage power is applied and flashes during polling over RS-485. On devices with events enabled in Fast Modbus ⚡ the indicator flashes more frequently than during sequential polling because events are polled faster. In bootloader mode, it flashes once per second; during firmware upload, it flashes rapidly. It is located beneath terminal B.

Installation

Mount the device on a standard 35 mm DIN rail.

The V+ GND A B terminal block, with a 3.5 mm pitch, connects the power supply and RS-485 communication bus. Correct bus wiring is essential for reliable communication; see RS-485 bus wiring and connection.

If devices on the RS-485 bus use different power supplies, their GND terminals must be interconnected. See Grounding Wiren Board devices and connecting GND and iGND.

Digital inputs activate when connected to iGND. The current is low (~2 mA), so any suitable button or switch type can be used. Cable length and cross-section are not critical for contact detection. To reduce interference from nearby power wiring, use twisted pair and connect iGND to the second conductor of the pair. More about connecting iGND/GND terminals.

Use twisted-pair cable to connect 0–10 V signals to actuators: one conductor for the signal and the other for GND.

Installation example

An installation example for the WB-MAO4 module is shown in Diagram 1.

In this example, the module controls two LED strip dimmers with 0–10 V inputs. It also reads a switch whose logic is implemented using rules on the controller. The module is powered by the controller and communicates with it over RS-485. The dimmers use a separate power supply.

WARNING: because the negative power terminal of WB-MAO4 is not isolated from the negative output terminals, you must connect the negative terminal of the module's power supply to the negative terminal of the load's power supply using a conductor with a cross-section of at least 1.5 mm² .

In this example, the module is powered by a Wiren Board 6 controller, so connect the negative terminal of the controller's power supply to the negative terminal of the load's power supply.

Wiren Board controller web interface

Selecting a template

To display the device on the Devices tab of the Wiren Board controller web interface, add it automatically by scanning for Wiren Board devices on RS-485 or manually by selecting the template WB-MAO4.

Controlling the device and viewing values

The web interface allows you to control device outputs and view readings. To change the displayed channels, edit the device configuration in the wb-mqtt-serial driver settings.

Configuration

Configuration methods

1. Set the parameters in the Wiren Board controller web interface under Settings → Configs → Serial devices driver configuration. If these items are unavailable, check your access level.
2. Write settings to the Modbus registers of the module from the controller console using the utility modbus-utils-rpc or modbus­_client.
3. Without a Wiren Board controller, use the Wiren Board device web configurator or other software; see Using Wiren Board Modbus devices without a controller. You will need a computer with an interface converter: USB-RS485.

Our devices are continually improved. If settings described in this manual are missing, update the device firmware and controller software.

Analog output configuration

You can change the following parameters:

• Outputs Mode — select 0–10 V or PWM mode.
• PWM Frequency Factor — the PWM factor. The resulting frequency is calculated as 24 kHz / Factor.

Output control

Setting an output voltage (in 0–10 V mode) or duty cycle (in PWM mode) immediately applies that value to the corresponding output.

Outputs can also be controlled as dimmers:

• switch them on or off;
• set the output level as a percentage of the configured range;
• set the rate of change of the output level.

Output parameters:

• Voltage at 1% dimming level (mV) — the output value corresponding to a level of 1 %.
• Voltage at 100% dimming level (mV) — the output value corresponding to a level of 100 %.
• Dimming level decrement rate (ms/%) / Dimming level increment rate (ms/%) — the rate at which the output signal level decreases or increases when changing from one value to another.
• Action repeat time (ms) — continuous actions repeat at the specified interval in milliseconds.

The increase/decrease time may be zero. This disables smooth transitions and applies the level immediately.

Mapping button events to outputs

Momentary pushbutton

WB-MAO4 has 3 digital inputs for buttons. Each button supports 4 press types: short, long, double, and short-then-long. This gives 12 events, each with two mapping parameters: the target output and the action type.

Output number selects the output affected by the event. Choose one output, all outputs, or none to ignore the event.

Output action selects what the event does:

• Off;
• On;
• Toggle;
• Increase level;
• Decrease level;
• Increase/decrease level. The action alternates each time the button is pressed.

Some combinations of events and actions have no practical meaning and are ignored. The controller driver template takes these restrictions into account.

Dimming step for single and double presses

Available from firmware 2.9.0

For increase-level and decrease-level actions assigned to a short or double press, you can specify the level adjustment step. Configure it separately for each channel and for short and double presses.

On a short or double press, the module changes the target level by the specified step. The transition is smooth and follows the settings of Dimming level increment rate (ms/%) and Dimming level decrement rate (ms/%).

Latching switch

Conventional latching switches can be used instead of push buttons. Select the Latching switch input mode. Two event types are available: switch on (closed) and switch off (open).

Output number selects the output affected by the event. Choose one output, all outputs, or none to ignore the event.

The following output actions are available:

• On;
• Off;
• Toggle.

Encoder support

Available from firmware 2.9.0

One AB quadrature (incremental) encoder can be connected to the WB-MAO4 inputs: Encoder 1 is connected to inputs 1/2. Input 3 is not part of the encoder and remains an ordinary digital input.

For each encoder input, configure Debounce time. Recommended debounce time: 2–5 ms; use 2 ms for fast rotation.

For modules manufactured before batch v2.9E, the encoder pulse rate must not exceed 20 pulses per second; otherwise counting errors may occur. We recommend encoders with up to 20 pulses per revolution and designing the control system so that rotation faster than 1 revolution per second is rare or impossible. This restriction does not apply from batch v2.9E onward.

AB encoders

AB encoders can control parameters such as lighting brightness.

Connect three wires: A, B, GND. Shaft position is available in the channel Encoder position and can range from −2147483648 to 2147483647. When either boundary is reached, the value wraps to the opposite boundary and counting continues.

Many encoders also have a Switch output that closes to GND when the shaft is pressed. Connect it to any free input and process it as an ordinary button.

Channel Encoder position is writable, allowing an initial position to be set.

Controlling the dimmer with an encoder

Open device settings and select the tab Encoders. Configure each encoder separately under Encoder 1.

In Encoder connection type, select AB.

Parameter Pulses per step sets how many A/B input pulses correspond to one logical encoder step.

In Controlled channel, select Control disabled or one of channels 1–4 to be controlled by encoder rotation.

Parameter Level adjustment step (%) sets the change per logical encoder step.

Parameter Behaviour below minimum level determines whether reducing the level below its configured minimum switches the channel off or retains the minimum level.

Lighting scenes

Scenes group several channels and assign actions to them. A scene can also contain a single channel.

For example, you need two lighting modes in a room:

1. day mode — rapid switching on at full brightness / rapid switching off;
2. night mode — slow switching on at low brightness / slow switching off.

Define 2 scenes and configure their actions:

• Scene 1
  • when the scene is switched on: switch on and set brightness to 100 %. Brightness transition time: 10 ms/%.
  • when the scene is switched off: switch off. Brightness transition time: 10 ms/%.
• Scene 2
  • when the scene is switched on: switch on and set brightness to 10 %. Brightness transition time: 200 ms/%.
  • when the scene is switched off: switch off. Brightness transition time: 200 ms/%.

Scene 1 now provides day mode and Scene 2 provides night mode. Scene switching can also be mapped to button presses: for example, a short press toggles Scene 1 and a double press toggles Scene 2.

Output channels with automatic switch-on

Available from firmware 2.9.0 Each output-control channel has an additional auto-on channel. It mirrors the ordinary channel, but writing a value greater than zero also switches the associated output on.

Behaviour:

• writing > 0 — switches the output on and sets the written value;
• Writing 0 — switches the channel off or resets its level in the same way as the ordinary channel;
• reading returns the current value of the corresponding parameter.

Auto-on channels are useful for scenarios and external integrations: one command sets the required level without a separate write to the coil to switch the channel on.

Safety Mode

Safety Mode can stop a process if control of the module is lost, for example because the RS-485 cable is severed. Account for communication loss when designing control systems.

The Safety Mode timer restarts after each successfully received and processed Modbus request. The module enters Safety Mode when the configured time expires and resumes normal operation when communication is restored. The default timeout is 10 seconds.

Each output has a configurable fail-safe state and can be configured to enter it on communication loss.

Input control behaviour can be configured:

• Do not block — configured input control remains available.
• Block in Safety Mode — inputs cannot control outputs during fail-safe operation.
• Allow only in Safety Mode — configured input control is available only in Safety Mode, not during normal operation.

Output states at power-up

For each channel, select its power-on behaviour:

• Switch off — after switching off, the channel can be switched on using its corresponding switch or by changing its level from 0 % to N %;
• Restore previous state — restores the channel state before the power loss;
• On;
• Set level — switches the channel on and sets the specified level. Setting 0 % switches the channel off; changing the level from 0 % to N % switches it on.

Modbus operation

Wiren Board devices use Modbus RTU. The physical connection uses the RS-485 interface.

interface. All main commands for reading and writing one or multiple registers are supported. See the list in the Modbus protocol description.

The module can be configured:

• in the Wiren Board controller web interface;
• using the Wiren Board device web configurator;
• using third-party software.

Default port settings

In current firmware, setting Stop bits is optional: the device also operates correctly when its number of stop bits differs from the Modbus master setting.

For a faster response, we recommend increasing the baud rate to 115200 bit/s; see Communication parameter settings.

Modbus address

Each device on the bus must have a unique address from 1 to 247. The factory-assigned address is printed on labels on the enclosure (top cover, side or underside). Devices in a production batch are assigned different addresses, so devices in one order will usually have different addresses.

For instructions on finding, changing or resetting the address, see Wiren Board device Modbus address.

Remote smooth level adjustment

Available from firmware 2.9.0

Without this feature, the master must implement smooth remote level adjustment by writing a new level to the register every few milliseconds. This adds traffic to the RS-485 bus and lengthens the polling cycle for other devices. With Auto-Change , the master writes an action to a Modbus register once, and the module then changes the level periodically, just as when a local button is held down.

Action register values:

• 0 — stop smooth adjustment;
• 1 — decrease the level;
• 2 — increase the level;
• 3 — alternate between decreasing and increasing the level. The initial direction is opposite to the last local long-press direction on this channel.

Smooth adjustment stops when the level reaches 1 % or 100 %, when the channel is switched off through its coil register, or when a lighting scene changes this channel's level. On stopping, the module resets the action register to 0.

The adjustment speed follows the local button action-repeat setting, which also determines adjustment while an input is held.

Fast Modbus extension

Fast Modbus extends standard Modbus with rapid discovery of Wiren Board devices on RS-485 and event polling.

These features are enabled by a special command from the master, so Wiren Board devices remain compatible with third-party equipment.

Not every register supports event generation. Check the register map: event-capable registers are marked with ⚡. See Fast Modbus.

Modbus register map

Firmware updates and resetting settings

Wiren Board devices support firmware updates over Modbus. This allows bugs to be fixed at the installation site and, where technically possible, new features to be added. Settings stored in the device are retained during a firmware update.

Instructions:

• Firmware update ()
• Resetting settings
• Connection parameter settings
• Modbus address: find, reset or change
• Updating the bootloader

New firmware releases are listed in the device firmware changelog.

Known issues

Hardware revisions

Images and drawings

• 
  WB-MAO4 control module PCB, version 2.0
• 
  Overall dimensions