Wiren Board 4: Hardware

Материал из Wiren Board
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Wiren Board 4



Technical specifications

Wiren Board 4


Software
Operating System Debian Linux 7.0. Mainline kernel 3.19.
Controller
CPU Freescale i.MX233 454 MHz
RAM DDR SDRAM 64 MB
ROM MicroSD card 32 GB max
Wireless Interfaces
Wi-Fi 802.11 b/g/n 2.4 ГГц
GSM/GPRS 900/1800 МГц. GPRS multi-slot class 10/8 max. 85.6 kbps (downlink). microSIM card, packaged
Radio module 433 MHz RFM69H module. To communicate with Noolite devices, Oregon sensors
Radio module 2.4 GHz NRF24L01To communicate with similar NRF24 modules (optional)
Wired interfaces
Ethernet 10/100 Mbit/s, RJ-45 connector
USB 2.0 Host 2 connectors (one connector is located inside the case)
Audiooutput 3.5 mm connector, stereo
2xRS-485 (one of the ports is insulated) Software support of Modbus RTU, ADICON/A-BUS/Uniel, and Smartbus G4 protocols
Debug console Debug UART To be connected via USB-UART adapter
2x 1-Wire Connection of temperature and moister sensors
Connection of sensors
5xADC 2x up to 24V , 3x - up to 5V
2xInputs for resistive sensors Connection of 10 kOhm thermistors. The controller can be used as ADC up to 3.3V
4x"Dry contact" Connection of pushbuttons, gerkons, counters with pulse outputs
2x DI (digital input)
Outputs
9x"Open collector" 24V/2A, control of contactors, LED strip lights, etc.
2xРеле Up to 250V/3A, normally open contacts
Other
8xGPIO are multiplexed with other inputs/outputs
1xSpeaker "buzzer"
Real-time clock RTC RTC Clock battery
Watchdog timer Separate hardware watchdog to perform full reset of the device
1x Connector for extension module Supported extension modules:
* RS-232 extension module
Power supply
Operating voltage 9-24 V
Power consumption <3 W (maximum 12 W)
Redundant battery Operation Li-ion batteries are supported
Passive Power over Ethernet Passsive Power over Ethernet
Overall dimensions board - 103x87x20 mm, housing for DIN rail installation 6U
Operation Operating temperature - 0..70C (-40..85C by request) Conformal coating of pcb for moister protection

Terminal blocks

Input and output protection scheme

Some terminal blocks can be used to perform more than one function. See the detailed description in the Port multiplexing article.

legend

Max. V, I state default Functions
Upper row, right block
Vin 24V Input voltage
GND
O1 Inputs/outputs of extension module
O2
O3
A 30 V 0V Non-isolated port RS-485
B 30 V +5V
(9-24)V_OUT 24V Input voltage (output) to power devices on RS-485 bus
GND
A-iso 30 V 0V Optically isolated RS-485 RS-485
B-iso 30 V +5V
GND-iso Ground of optically isolated RS-485
Lower row, left block
5V out 5V, 0.5A 5V output 5V (for 1-Wire sensors)
W1 30V 3.3V 1-Wire, GPIO
W2
R1 5V High Z Resistive sensors,ADC, digital inputs (GPIO) without retightening
R2
A1 Vin , 2A High Z "Open collector" outputs, ADC
A2
A3
A4 Vin , 2A High Z "Open collector" outputs, ADC , digital inputs DI
A5
GND
Lower row, right block
GND
GND
D1 Vin , 2A +5V "Open collector" outputs, "dry contact" inputs
D2
D3
D4
Relay1 250, 2A is open first relay
Relay2 second relay

Input protection

As compared to previous versions, input protection and general noise immunity are significantly improved.

  1. All inputs are protected from applying the power supply voltage (up to 24 V) and transient noise.
  2. Wiren Board 4 is protected against reverse polarity.
  3. Wiren Board 4 features one optically isolated RS-485 interfaces.
  4. Low-side FET switches on Ax and Dx inputs are protected from negative voltage spikes from inductive loads.
  5. Relays have sparking suppression circuits



Multifunctional inputs/outputs Ax and Dx

Equivalent circuit of A1-A3 channels
Equivalent circuit of A4-A5 channels
Equivalent circuit of Dx channels

Multifunctional channels consist of input and output stages are connected in parallel, as well as protective diodes (connected to one terminal of the channel).

Output stage consists of the Tx switch. The Tx switch can connect the corresponding output with ground.

The state of the switch is controlled by logic circuits inside the controller. The switch may be one of 2 states:

  • Active (closed); channel output is connected to ground (0V)
  • Inactive (open), high impedance.

Such outputs are called “open collectors”.

Input stage of Ax channel consists of an analogue-to-digital converter ADCx and an input resistor Rx.

The ADC has a high impedance, so it doesn't affect the channel operation even if the channel works as output.


In input mode the Tx switch is inactive (open) and, thus, does not affect voltage measuring at the channel terminals. Input resistance of the channel in input mode is determined by the Rx resistance.

If the channel terminal is left floating, the input voltage measured by ADCs is pulled down to zero by the Rx resistance.

А4 and А5 support binary input function DI: more than 3V at the terminal is considered as triggering of the input.

Input stage of Dx channels consists of a circuit for connection of dry contacts. This stage continuously provides 5V voltage at the terminal. In input mode the Tx key is inactive (open). When the terminal is grounded, small current (2 mA) flows via the channel. Controller considers that as triggering of the input. Closing of the Tx key is considered as triggering of the input. In output mode the output stage does not affect the channel operation, provided that a more than 5 V load is connected to the channel.



Resistive Inputs

Each terminal is connected to internal adjustable current source. The controller measures current flowing through the sensor and simultaneously measures the terminal voltage to calculate the resistance value. If necessary and if the corresponding program is available, resistive inputs may be used as additional analogue/binary ones.



Extension modules

Ref. the corresponding articles to describe connection and software operation:


Power Supply

Блок-схема питания WB 4



External power source

Allowed voltage range is 7-24 V. Average power consumption of the board is 1.5-2 W, but the GSM module may temporally consume up to 8 W. Therefore, it is recommended to use at least 10 W power sources.

A standard connector jack 5.5x2.1 mm is provided for connection to the power source. Input power can also be connected to Vin and GND terminals.



Power over Ethernet

It is possible to power the device via an Ethernet cable. Ref.Power over Ethernet.



Battery

It is possible to connect Wiren Board to a Li-Ion (Li-Pol) battery with maximal voltage of 4.2 V. When the device is connected to a power source, the battery is charged with up to 0.5 A current.

The battery is provided from charging at negative temperature. However, it is not protected from overcharge, and thus it is strongly recommended to use batteries with internal protection boards.


It is necessary to meet the battery polarity!



Working with WAGO 250 terminal blocks

Working with WAGO 250 terminals

Self-tightened clips of WAGO 250 Series are used as interface terminals of the controller. When a stripped single-core wire is inserted into a clip, it is automatically caught by a spring latch. In order to insert multi-core wires, it is necessary to press the clip button to compress the spring. The button is provided with a slot suitable for a flat screw-drive. In order to remove the wire, it is necessary to press the clip button to compress the spring, and then pull the wire out of the clip.



Wi-Fi, GSM, 433MHz antennas

Wi-Fi antenna is located inside the casing.

GSM and 433 MHz radio antennas are connected to SMA connectors on the casing.

If GSM signal is weak, it is recommended to use an external antenna and to locate it far from the controller.



Peripheral devices connection diagrams

Example of relay connection
Example of button connection


Low voltage load control

12/24V relays, LEDs, fans, indicator lamps, etc.

Power supply voltage of the controller must not be lower than voltage of the connected load. Connect "+" of the load to "+" of the power source, and "-" to Ax or Dx terminals. If several channels are used, and their total current exceeds 5 A, connect several GND terminals to "-" of the power source. Voltage spikes occur when the device controls an inductive load (relay). In order to protect the controller from overload, it is equipped with built-in protective diodes. No external protective elements are necessary.


Electric contactors with control voltage of 220 V

Connect the control coil of the contactor via WB relay (ref. fig.). The WB relay is equipped with a damping RC-circuit and a TVS. No external components are necessary.



Analogue voltage output sensors

Connect the device ground to the GND terminal or a common grounding bus. Connect the sensor output to Ax or Rx terminal. Ах/Rx channels feature different ranges of measured voltages. Select the optimal channel for your sensor.



Analogue current output sensors

WB is not equipped with special current inputs, but it is possible to convert current to voltage by means of 100-300 Ohm resister and use the connection diagram described above.



Resistive output sensors

Inputs R1 and R2 are intended for measuring of resistance in a range of 1-100 kOhm. The measured resistor must be connected to GND and Rx terminals.



Pulse output sensors, counters and buttons

These devices from output signals by closing two wires they are connected to. Connect one wire to the GND terminal or a common grounding bus. Connect the other wire to the Dx terminal. Some counters are equipped with an optron based pulse output. In such cases it is necessary to take polarity of the wires into account. The negative wire must be connected to GND, while the positive one must be connected to Dx.


“Open collector” output devices

Both device and controller must be connected to the common grounding bus. Connect the "open collector" output to the Dx terminal.



Network connection of 1-Wire

Connect the device ground to the GND terminal or a common grounding bus. Connect the data line to one of 1-Wire terminals. Connect the power line to 5V terminal (internal power source). It is allowed to use external power sources of 1-Wire bus.

If a passive power source is used, the power terminals of all sensors must be connected to the grounding bus. In such cases the bus will consist of two wires connected to 1-Wire and GND, respectively.



RS-485 network connection

See RS-485.

Wiren Board 4 controllers are equipped with two RS-485 ports. One of them is galvanic insulated, the other one is not. If the RS-485 network is quite large, it is better use the insulated port for connection. Lines A and B are connected to A and B terminals, respectively. The signal ground (if any) must be connected to the GNDiso terminal.

A and B lines are often accompanied by another pair of wires used to power devices connected to the bus. In such cases it is necessary to use GND and Vout terminals. Current in power wires must not exceed 1 A.



Example of device connection

Schematic test stand -
Schematic test stand

Schematics and Drawing

Wiren Board 4 principle diagram - Файл:WB 4.3.pdf, scheme - Файл:WB 4.2 чертеж.pdf