Sensors Modbus Management/en

Modbus parameters

Modbus address

Modbus-the 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 Wirenboard devices.

Modbus commands supported by the device

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

Holding Registers

Register/ address	Type	Read/ write	default or error Value	Format	Purpose	Supported in					From version insertions
						WB-MS (model code)	WB-MS v2 (model code)	WB-MSW	WB-MSW2	WB-MSW V. 3
0	input	R	0x7FFF	°C × 10 (signed)	Temperature with built-in sensor	T	-	-	+	+
1	input	R	%RH × 10 (signed)	relative humidity with built-in sensor	H	-	+	+	+
2	input	R	-	LC	"(register is not used in WB-MSW sensors, registers 9 and 10 instead)" Illumination from built-in sensor	L	Lux	-	-	-
3	input	R	-	dB × 100	Noise level multiplied by 100	S	-	+	S	S
4	input	R	0x7FFF	°C × 100 (signed)	Temperature with built-in sensor	+	+	-	-	+	4.2
5	input	R	-	%RH × 100 (signed)	Relative humidity with built-in sensor	+	+	-	-	+	4.2
6	input	R	0x7FFF	°C × 16 (signed)	Temperature from external sensor	D	+	-	-	-
7	input	R	0x7FFF	°C × 16 (signed)	Temperature from external sensor	D	+	-	-	-
8	input	R	0xFFFF	PPM	CO2 concentration	-	-	After	C
9-10	input	R		LC	The illumination, multiplied by 100 (9 - high-order, 10 — LSB luminance values)	-	-	+	L
11	input	R	0xFFFF	PPM	Air quality	-	VOC	-	-	+
88	holding	RW	0	ppm (400-1500)	Service register, doesn't present in most devices. Manual calibration of CO2 sensor. For calibration, write down here the current CO2 concentration measured by another instrument	-	-	-	C	C	3.12
89	holding	RW	0xFF	days'	Service register, doesn't present in most devices. Cycle time for co sensor self-calibration algorithm (ABC)	-	-	-	C	C	3.12
90	holding	RW	20 (200 ms)	× 10 ms	light averaging Time	L, B	-	-	-	-
91	holding	RW	20 (200 ms)	× 10 ms	Noise averaging time	S	-	+	S	S
95	holding	RW	1	1 or 0	CO2 sensor (ABC) auto-calibration to atmospheric CO2	-	-	-	After	C
96	holding	R	2000 / 5000	ppm	(available from firmware version 3.5.0) CO2 concentration measurement Range. Valid values: 2000, 5000, 10000.	-	-	-	C	C	3.5.0
91	holding	RW	20 (200 ms)	× 10 ms	Время усреднения шума	S	-	+	S	S
92	holding	RW	0	x0.0625	Служебный регистр HOLD_REG_SPL_RAW_OFFSET - сдвиг значения АЦП	-	-	S	S	S	4.9.0
93	holding	RW	0	x0.1dB	Служебный регистр HOLD_REG_SPL_OFFSET - поправка к значению уровня шума	-	-	S	S	S	4.9.0
95	holding	RW	1	1 or 0	Режим автокалибровки датчика CO2 (ABC) на атмосферный уровень CO2	-	-	-	С	C
96	holding	R	2000 / 5000	ppm	(доступно с версии прошивки 3.5.0) Диапазон измерения концентрации CO2. Допустимые значения: 2000, 5000, 10000.	-	-	-	C	C	3.5.0
97	holding	RW	0 — 10	c	Period between flashes of signal LEDs	-	-	-	-	+	3.13.0
98	holding	RW	0 — 50	MS	Led flash duration	-	-	-	-	+	3.13.0
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). The values are discarded if the previous value differs from the suspicious value by more than * 0.0625 C. Write 0 to disable the filter.	D	+	-	-	-	3.10.0
100	input	R			Служебный регистр HOLD_REG_SPL_RAW_INT	-	-	S	S	S
101	input	R			Service register HOLD_REG_TH_READS	all
102	input	R			Service register HOLD_REG_TH_ERRORS	all
103	holding	RW			Служебный регистр HOLD_REG_ILLUMINANCE_MODE	+	+	+	-	-
104-105	input	R		32-bit unsigned int	uptime counter in seconds	all
106	input	R			Service register INPUT_REG_SGPC3_BASELINE	-	-	-	-	+
107	input	R			Service register INPUT_REG_SGPC3_RAW_SIGNAL	-	-	-	-	+
108	input	R	0xFFFF		Sgpc3 VERSION service register	-	-	-	-	+	4.2
110	holding	RW	96	baud rate / 100	RS-485 port speed, divided by 100. Permissible speeds: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 (Configure RS-485 communication parameters for Wiren Board Modbus devices)	all					>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)	all
112	holding	RW	2		number of stop bits of RS-485 port. Valid values: 1, 2	all
120 (0x78)	holding	RW	0	non-0	writing to the register causes the module to restart without saving state	all
121 (0x79)	input	R	-	mV	current supply voltage of the module	all
128 (0x80)	holding	RW	1		Modbus device address	all
129 (0x81)	holding	RW	0	0 or 1	Go to bootloader mode	all					4.5.0
200-206	input	R	see Device signature		signature	all
220-241	input	| | | _date__ _time__	firmware build date	all
245	holding	RW	0	°C × 100 (signed)	Self-heating temperature compensation for temperature and humidity sensor (value is subtracted from measured temperature)	+	-	-	-	+	4.2
250-269	input	| | / string, null-terminated	firmware version	all
270-271	input	R		32-bit unsigned int	unique identifier (S/N)	all
280	input	R			Maximum value of motion sensor with ADC	-	-	-	-	+
281	input	R			Value of the motion sensor with ADC	-	-	-	-	+
282	holding	RW	10	s	The width of the time window for calculating the maximum average value of the motion sensor (from 1 to 60 seconds)	-	-	-	-	+
283	input	R			Current average value of movement in conventional units	-	-	-	-	+

Coils

Registers related to IR control are described in WB-MSx_Consumer_IR_Manual/en.

Starting address	Quantity	Purpose	In modifications	From firmware version
0	1	Enable buzzer (buzzer)	WB-MSW v.3, WB-MSW2
1	1	Forced calibration of the built-in CO2 sensor. Turn on after 20 minutes of operation at a CO2 level of 400 ppm	WB-MSW v.3, WB-MSW2
2	1	Turn on the heating (heater) in the temperature and humidity sensor chip HDC1080	WB-MS, WB-MSW v.3, WB-MSW2	3.2.0
3	1	Power on/off of the CO2 sensor	WB-MSW V. 3	4.1.0
10	1	Green led on	WB-MSW v.3
11	1	Enable red led	WB-MSW v.3

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:

Module	Signature
WB-MS	WBMS,'0x00','0x00'
WB-MSW	WBMSW,'0x00'
WB-MSW2	WBMSW2
WB-MSW v.3	WBMSW3

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.

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.

Register reading example

Let's check whether it is true that we are connected to the module of the desired type. (Module wb-mqtt-serial needs to 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 hexadecimal answer into a character string:

echo  -e `modbus_client --debug -mrtu -pnone -s2 /dev/ttyRS485-1 \
-a1 -t0x03 -r200 -c 6 | \
grep Data | sed -e 's/0x00/\\\x/g' -e 's/Data://' -e 's/\s//g'`

As a result of the command we receive string WBMS. The WB-MS module in the example has Modbus address 1.