View source for WB-M1W2 1-Wire to Modbus Temperature Measurement Module/en

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[[Файл:WB-M1W2.jpg|мини|WB-M1W2]]
[[Файл:WB-M1W2_new.png|мини|WB-M1W2, v.2]]

{{#vardefine:ProductFullName1|1-Wire WB-M1W2 bus coupler}} {{#vardefine:FileName1|WB_M1W2}} {{#vardefine:ProductName1|WB-M1W2}} 
'''[https://wirenboard.com/en/product/WB-M1W2/ Buy online]'''

WB-M1W2 is a compact bus coupler, designed for polling '''two''' digital 1-Wire 
 thermometers (DS18B20) via Modbus RTU Protocol on RS-485 bus.

== Inputs== 
The module is powered by screw terminals V+ and GND, RS-485 line is connected to inputs A and B.

'''Version 1:''' Two external DS18B20 temperature sensors are connected via a parasitic power supply circuit, when the +5V and GND pins are connected to the GND terminal, the data output is connected to 1-Wire terminal 1 or 2.

 
'''Version 2:''' Two external temperature sensor DS18B20 is connected on an active power circuit, connect the sensor GND to the GND terminal, a data output connected to terminal 1 or 2 1-Wire, the sensor supply voltage is applied from the output to 5V out. In version 2 there is an additional protection of inputs 1-Wire.

Also, the device has an internal temperature sensor (NTC-thermistor).

In firmware version 4.0.0 and higher, it is also possible to configure the 1-Wire inputs of the module as discrete or counting inputs.

==Installation==
[[File:WB-M1W2+DS18B20.png|650px|thumb|center|Connect DS18B20 sensors to WB-M1W2 v.1 (left) and v. 2 (right)]]
The converter is installed in cable channels, boxes, soldering boxes. The recommended line length from the transmitter to the 1-Wire remote sensors is no more than 30 meters.

== Specifications ==
{| class="wikitable"
! style="text-align: center;" | Option
! style="text-align: center;" | Value
|-
! colspan="2" |Power
|-
|Supply voltage
|9 — 24 V DC
|-
|Power consumption
|
0.1 W 
|-
!colspan="2" | '''Terminals and wire section'''
|-
|| Recommended wire cross-section with tips, mm<sup>2</sup>|| 0,75 — 1
|-
|| Length of the standard sleeve tips, mm || 8
|-
|| Torque of screws, N∙m || 0,2
|-
! colspan="2" |Sensors
|-
| External sensor
| Can connect two DS18B20 digital temperature sensors.
|-
|Internal sensor
|Built-in NTC thermistor
|-
! colspan="2" |Inputs (connect instead of external sensors)
|-
|Number of digital inputs
|2
|-
|Input type
|Dry contact, uninsulated
|-
|Tension in the open position
|3.3 V
|-
! colspan="2" |Control
|-
|Management interface
|RS-485
|-
|Interface isolation
|Uninsulated
|-
|Communication protocol
|Modbus RTU, address is set by software, factory settings are indicated on the label
|-
|RS-485 interface parameters
| 
speed 9600 bps; data bits 8; parity N; stop bits 2; 
Starting from firmware version "'3.1.0"' parameters interfaces can be configured programmatically:
*Speed: 1200, 2400, 4800, 9600 (default), 19200, 38400, 57600, 115200 bit/s <br>([[UART_Communication_Settings|configure RS-485 communication parameters for wiren Board modbus devices]])
*Data: 8 bit 
*Parity check: none (default), 1 - odd (odd), 2 - even (even) 
*Stop bits: 2 (default), 1
|-
! colspan="2" |dimensions
|-
| Size
|
* 40x15x11 mm;
|-
! colspan="2" |operating Conditions
|-
| Air temperature
| -40°C to +80°C
|-
| Relative humidity
| up to 98%,without moisture condensate
|}

== Additional functionality==

'''Address change''' is broadcast (slave_id 0) team record (WRITE_SINGLE_REGISTER) to holding register with address 128 (0x80).

At adress 200 lies 6 bytes '''signature'''. The signature is unique for each device model and allows you to identify the model.
To obtain the signatures necessary to fulfill READ_HOLDING_REGISTERS, address 200, length 6.  
Writing to this area of memory is not supported and error 3 is returned when attempting to write to an invalid location.

== Register map ==

{| class="wikitable"
! rowspan="2" |Register/ address
! rowspan="2" |Type
! rowspan="2" |Read/ write
! rowspan="2" |Default
! rowspan="2" |Format
! rowspan="2" |Purpose
!Versions
insertions
|-
!
|-
|6
|input
|R
|0x7FFF
|°C × 16 (signed)
|Temperature with built-in sensor
|
|-
|7
|input
|R
|0x7FFF
|°C × 16 (signed)
|Temperature from the first external 1-Wire sensor
|
|-
|8
|input
|R
|0x7FFF
|°C × 16 (signed)
|Temperature from second external 1-Wire sensor
|
|-
|20
|input
|R
|0
|°C × 16 (signed)
|Temperature from the first external 1-Wire sensor. In case of an error, the sensor retains the previous valid value (sensor status read from the discrete register 16).
| rowspan="2" |starting with firmware 4.6.0
|-
|21
|input
|R
|0
|°C × 16 (signed)
|Temperature from the second external 1-Wire sensor. In case of an error, the sensor retains the previous valid value (sensor status read from the discrete register 17).
|-
|99||holding||RW||16|| 1 = 0.0625 C
||(available from firmware version 3.10.0) 
Suspicious value filter for 1-Wire sensors (85.000 C, 127.937 C). 
Values are discarded if the previous value differs from the suspect value by more than * 0.0625 C. 
Write 0 to disable the filter.
|3.10.0
|-


| 104-105 || input || R|| || 32-bit unsigned int || uptime counter in seconds |
|-



|110
|holding
|RW
|96
|baud rate / 100
|RS-485 port speed, "'divided by 100"'. Permissible speeds: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
| rowspan="3" |>3.1.0
|-
|111
|holding
|RW
|0
|
|configure the RS-485 port parity bit. Valid values: 0 - no parity bit (none), 1 - odd (odd), 2 - even (even)
|-
|112
|holding
|RW
|2
|
|number of stop bits of RS-485 port. Valid values: 1, 2
|-
|
|
|
|
|
|
|
|-
|120 (0x78)
|holding
|RW
|0
|other than 0
|write to the register causes a reset of the module without saving state
|
|-
|121 (0x79)
|input
|R
| -
|mV
|current supply voltage of the module
|
|-
|128 (0x80)
|holding
|RW
|1
|
|The Modbus address of the device
|
|-
| 129 (0x81) || holding || RW|| 0 || 0 or 1 || Go to [[WB-MCU-Flasher|bootloader mode]] || starting with firmware 4.5.0
|-
|200-206
|input
|R
|see [[Sensors Modbus Management/en|Device signature]]
|
|signature
|
|-
|220-241
|input
|R
|
|__date__ _ _ time__
|the build date of the firmware
|
|-
|245
|holding
|RW
|216
|°C × 100 (signed)
|Self-heating compensation of the built-in temperature sensor.
The register value is subtracted from the temperature measured by the built-in sensor (register 6)
|
|-
|250-269
|input
|R
|
|string, null-terminated
|firmware version
|
|-
|270-271
|input
|R
|
|32-bit unsigned int
|unique identifier (S/N)
|
|-
|
|
|
|
|
|
|
|-
|275
|holding
|RW
|0
|0 or 1
|Input mode # 1: 0 - 1-wire, 1 - discrete input
| rowspan="6" |>=4.0.0
|-
|276
|holding
|RW
|0
|0 or 1
|Input mode # 2: 0 - 1-wire, 1 - discrete input
|-
|277
|input
|R
|
|16-bit unsigned int
|Counter for input #1
|-
|278
|input
|R
|
|16-bit unsigned int
|Counter positives for the entrance №2
|-
|0
|discrete
|R
|
|0 or 1
|Current state of input #1: 0 - open, 1 - closed on GND. If 1-wire mode is selected for input, the value is always 0.
|-
|1
|discrete
|R
|
|0 or 1
|Current state of input #2: 0 - open, 1 - closed on GND. If 1-wire mode is selected for input, the value is always 0.
|-
|16
|discrete
|R
|
|0 or 1
|Sensor polling status 1-Wire input no. 1: 0 - sensor not connected, 1 - sensor connected and correctly polled
| rowspan="2" |starting with firmware 4.6.0
|-
|17
|discrete
|R
|
|0 or 1
|Sensor polling status 1-Wire input no. 2: 0 - sensor not connected, 1 - sensor connected and correctly polled
|}

== Device signature ==

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:

{| class="wikitable"
! style="font-weight: bold;" | Module
! style="font-weight: bold;" | Signature
|-
| WB-M1W2
| WBMIR'0x00'
|}

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 ''number'''x00'''time'''x00''''' as a string (example: 'Jan 27 2017 17:01:13'). The length of the record is 21 registers.

== Operation of the transmitter with the Wiren Board controller ==
For Converter WB-M1W2 in the Wiren Board controller is equipped with the corresponding pattern for WB-M1W2.

Description of the channels of the template
{| class="wikitable"
! Channel name
!Appointment
|-
|Input Voltage||module supply Voltage
|-
|Internal Temperature Sensor||Internal/external digital temperature sensor. If the sensor is missing or defective, its name is highlighted in red.
|-
|External Sensor 1
|Temperature of an external digital sensor connected to port 1. If the sensor is missing or defective, its name is highlighted in red.
|-
|External Sensor 2
|Temperature of an external digital sensor connected to port 2. If the sensor is missing or defective, its name is highlighted in red.
|-
|Serial NO||module Serial number may be required when contacting technical support.
|-
|}

Since firmware version 4.0.0, the WB-M1W2 Converter allows you to configure each of the two inputs as a discrete input. The input mode is set in registers 275-276 (see the table above). In Wiren Board controllers this mode is configured through the Setup-section of the driver.

To display the registers corresponding to the discrete inputs, select the template "WB-M1W2 DI": 

[[File:M1w2 as discrete inputs example.png|400px|thumb|center|Example of WB-M1W2 configuration for discrete inputs.]]

Channels of discrete inputs (do not forget to put the inputs in discrete mode, as written above):
{| class="wikitable"
! Channel name
!Purpose
|-
|Discrete Input 1
||Input status 1. 0 - open, 1 - closed on GND
|-
|Discrete Input 2
||Input status 2. 0 - open, 1 - closed on GND
|-
|Counter 1
|Input operation counter 1
|-
|Counter 2
|Input counter 2
|}

== 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/en| Modbus client]]. Access to the command line is described in [[SSH/en| SSH]].

=== Register reading example ===
Let's check whether we are connected to the module of the desired type. (Module wb-mqtt-serial should be stopped). At address 200, a unique signature of 6 registers is stored. Let's read 6 registers, starting with the address 200, and convert the received answer from hexadecimal digits into a character string:

<syntaxhighlight lang="bash">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'` </syntaxhighlight>

As a result of the command, we receive string  '''WBM1W2'''. The WB-M1W2 module in the example has Modbus address 1.

== Device firmware update ==
Starting with the new firmware versions of the device, the firmware update functionality (firmware) via the Modbus Protocol is supported. This makes it possible to extend the functionality of the devices and eliminate errors in the firmware directly at the installation site. Read more about flashing devices described in the article [[WB-MCU-Flasher|Download firmware to Wiren Board devices]]. A list of firmware versions that support the update, as well as devices for which this feature is implemented, can be found in [[Firmware_Changelog/en| Firmware Changelog]].

== Images and drawings of the device ==
{{Wbincludes:WBPictures|1}}