Relay Module Modbus Management/en

Modbus parameters

Modbus address

Modbus-address set on manufacture

Modbus-address of the Wiren Board devices is easy to determine — it is printed on the sticker (the address is in decimal format). The new address of the device is written by the command WRITE_SINGLE_REGISTER to the storage register (holding register) with the address 128 (0x80). For details on how to determine (if the address has been changed) or change the Modbus address of the module, see Define and change the Modbus address of Wiren Board devices.

Modbus commands supported by the device

The Wirenboard relay modules support all major Modbus commands. Read more here: Register reading and writing function codes.

Safe mode

In this mode, when the Modbus communication is terminated, the device disconnects the relay after a specified time.

To enable Safety timer, you must write a value other than 0 to the storage register with the WRITE_SINGLE_REGISTER command at 8. This value is a timeout in seconds. A value of "0" disables safe mode.

Relay operation in case of power failure

In the latest firmware versions (starting with 1.5.3) for WB-MR devices, it is now possible to remember the output status when power is off. The mode is controlled by the Modbus register 6. If the register is set to '0', the state of the outputs will not be saved and all relays will be switched off when power is supplied. If the entry in the register unit, when the power is resumed everything is included before the crash relay is switched on again.

Digital inputs

The input state can be obtained by reading the Discrete Inputs 0—x registers (where x = (number of managed channels - 1)). If the input is connected to GND, the register value is 1, if not connected - it's 0.

Modes of interaction between digital inputs and relay outputs

You can enable direct control of the relay outputs from the digital inputs in the relay module. There are several options for such management:

• Simple:
  • Mode 0: managing switch without detent (click "self-released back"). You press the button (close the digital input with GND), it is "pressed back", the relay state is switched to the opposite.
  • Mode 1: switch control with locking. The relay is always set according to the position of the switch. If the switch is "on" (closes the digital input with GND), the relay is also closed. If the switch is "off", the relay is open.
  • Mode 3: relay output control from digital input is disabled.
• Complex:
  • Mapping-matrix (see detailed description below)

The mode can be set separately for each channel. To do this, register 5 must have a value of "0", and the mode for each channel is written to the storage registers starting from address 9 for the first channel, etc.

There is an outdated method - setting the mode for all channels at the same time. To do this, write the appropriate number in the storage register with address 5.

Mapping-matrix

Starting from firmware v.1.9.0, mode 2 is also provided for individual channels-disable all outputs, and operating modes (4 and 5) in accordance with the mapping matrix (see below).In this and later versions of firmware versions modules have flexible settings of the interaction of inputs and outputs of relay modules using a special mapping matrix: a table in which for each input is encoded change of any relay output state when the state of this input changes. A detailed description can be found in I/O Mapping Matrix.

Relay module register card

• x — number of relay outputs;
• y is the number of digital inputs.

(for modules WB-MRM2 see registers map at the description page of this module)

Register / address	Type	Read-write	Default	Format	Appointment	Note
0 .. (x-1)	coil	RW	-	1 or 0	relay status with number 1 .. x
0 .. (y-1)	discrete	R	-	1 or 0	entry status with number 1 .. y
5	holding	RW	0	0: buttons without locking 1: switch with lock 3: disable interaction	mode of interaction of digital inputs with relay outputs. The input status registers and the pressure counter continue to operate in all modes.	The register was used in the old configuration mechanism. It is recommended to leave it set to 0 and the inputs are configured via the individual registers 9 .. (9+x-1)
6	holding	RW		0: do not restore relay state after power is restored 1: restore relay state after power is restored	relay operation mode in case of power failure	(only in firmware 1.5.3 and later)
8	holding	RW	0	seconds	safe mode timeout
9 .. (9+x-1)	holding	RW	0	0: non-locking buttons 1: switch with lock 3: disable interaction	single digital input interaction mode with corresponding relay output; "0" should be written in register 5
				2: disable all relays when pressed 4: to operate in accordance with the I/O mapping- matrix 5: to operate in accordance with the I/O mapping-matrix, after 20 minutes to re-simulate the input state		Since firmware v.1.9.0
			1			Since firmware v.1.12.0
16	holding	RW		0: non-locking button 1: switch with lock 3: disable interaction	digital input operating mode 0 to disable all relays
			2	2: disable all relays when pressed 4: to operate in accordance with the mapping-matrix 5: to operate in accordance with the mapping-matrix, after 20 minutes to re-simulate the input state	digital input mode 0; register 5 must be set to "0"	Since firmware 1.9.0
32 .. (32+y-1)	input	R	0	16-bit unsigned int	input counter 1 .. y
104-105	input	R		32-bit unsigned int	uptime counter in seconds
120 (0x78)	holding	RW	0	other than 0	writing to the register causes the module to restart without saving the state
121 (0x79)	holding	R	-	mV	module current supply voltage
128 (0x80)	holding	RW	1	1 — 247	Modbus device address
129 (0x81)	holding	RW	0	0 or 1	Go to bootloader mode	1.10.0
200-205	holding	R	{'X','X','X','X','X','X'}		device signature (see table below)
220-241	holding	| | / _date__ _ _ time__	firmware build date
250-266	input	R		string, null-terminated	firmware version
270-271	input	R		32-bit unsigned int	unique identifier (S/N)
384-447	holding	RW	0		registers mapping-matrix	Since firmware version 1.9.0

In firmware version 1.6.0 and later, additional registers for setting data exchange parameters via RS-485 are supported:

Register / address	Type	Read/write	Value by default	Format	Function
110	holding	RW	96	baud rate / 100	RS-485 port speed, divided by 100. Permissible speeds: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 (UART Communication Settings for Wiren Board devices )
111	holding	RW	0		set the parity bit of the RS-485 port. Valid values: 0 - no parity bit (none), 1 - odd , 2 - even
112	holding	RW	2		umber of stop bits of RS-485 port. Valid values: 1, 2

The 6-byte module signature is stored at address 200. The signature is unique for each model of Wiren Board devices and allows to identify the model by Modbus:

Module	Signature
WB-MRPS6	MRPS6
WB-MR6C	WBMR6
WB-MR3xV	WBMR3
WB-MR6xV	WBMR6
WB-MR14	WBMR14
WB-MR11	WBMR11
WB-MRM2	WBMR2 WBMR2m

To get the signature of a device you need to run command READ_HOLDING_REGISTERS at 200 (length of 6 registers). Writing to this area of memory is not supported, and error 3 is returned when attempting to write to an invalid location. Empty spaces in the signature text are clogged with the value 0x00. Starting from register 220, the firmware build date is recorded, in the format numberx00timex00 as a string (example: 'Jan 27 2017 17:01:13'). The length of the record is 21 registers.

The status value of each relay is stored in flag registers (coil). The 1st relay register address is 0, the 2nd it's 1, etc.

Command-line device management

The Wiren Board controller software includes modbus_client utility to work with devices connected to the RS-485 outputs, via Modbus Protocol, the detailed description of the command is on the page Modbus client. Access to the command line is described in SSh.

Пример чтения регистров

Проверим, верно ли, что мы подключились именно к модулю нужного типа. (Сервис wb-mqtt-serial должен быть предварительно остановлен). По адресу 200 хранится уникальная сигнатура длиной в 6 регистров. Прочтем 6 регистров, начиная с адреса 200, и преобразуем полученный шестнадцатеричный ответ в символьную строку:

echo  -e `modbus_client --debug -mrtu -pnone -s2 /dev/ttyAPP1 \
-a1 -t0x03 -r200 -c 6 | \
grep Data | sed -e 's/0x00/\\\x/g' -e 's/Data://' -e 's/\s//g'`

В результате выполнения команды получаем строку, например WBMR6. Релейный модуль WB-MR6 имеет Modbus-адрес 1.

Выбор типа управления внешними входами

В релейных модулях предусмотрено два режима управления каналами реле: с помощью внешних входов и по протоколу RS-485. В релейных модулях можно выбрать режим 0, когда ко внешнему входу подключена кнопка (без фиксации), или режим 1, когда для управления используется обычный выключатель (с фиксацией). Режим 3 отключает внешнее управление, но при этом все равно сохраняется возможность управления по RS-485 и чтение состояния внешних входов. По умолчанию включен режим 0.

В режиме внешнего управления реле срабатывает по падению логического уровня: к внешним входам подключены резисторы подтяжки к линии +5V и реле соответствующего канала срабатывает при соединении входа с GND. Состояние реле каждого канала хранится в памяти контроллера до перезагрузки, по умолчанию при включении питания все реле выключены. После инициализации модуля опрашиваются внешние входы и реле всех каналов переводятся в соответствующее состояние.

Тип внешнего управления можно выбрать для каждого канала отдельно через регистры 9 — (9+x). Для этого в holding-регистре 5 должно быть записано значение 0:

modbus_client --debug -mrtu -pnone -s2 /dev/ttyAPP1 -a1 -t0x06 -r5 0

Инициализировать регистр при старте можно и через настройки web-интерфейса, смотрите страницу RS-485:Настройка_через_веб-интерфейс.