Matter Specification - Water Content Measurement Clusters

Matter :: Water Content Measurement Clusters

This is a base cluster. The server cluster provides an interface to water content measurement functionality. The measurement is reportable and may be configured for reporting. Water content measurements include, but are not limited to, leaf wetness, relative humidity, and soil moisture.
일반적인 상대습도 센서 뿐만 아니라 식물의 잎사귀 습도 센서, 토양 수분 센서 등 농작물 관리 IoT 디바이스를 위한 클러스

1. Classification

Hierarchy	Role	Scope	PICS Code
Base	Application	Endpoint	RH

2. Identifier

Identifier	Name	Measurement Type
0x0405	Relative Humidity Measurement	Percentage of water in the air
0x0407	Leaf Wetness Measurement	Percentage of water in the leaves of plants
0x0408	Soil Moisture Measurement	Percentage of water in the soil

3. Attributes

3.1. Measured Value

ID	Name	Type	Constraint	Quality	Default	Access	Conformance
0x0000	MeasuredValue	uint16	MinMeasuredValue to MaxMeasuredValue	XP		R V	M

MeasuredValue represents the water content in % as follows:

MeasuredValue = 100 x water content

Where 0% < = water content < = 100%, corresponding to a MeasuredValue in the range 0 to 10000.
The maximum resolution this format allows is 0.01%.
MinMeasuredValue and MaxMeasuredValue define the range of the sensor.
The null value indicates that the measurement is unknown, otherwise the range SHALL be as
described in Measured Value.
MeasuredValue is updated continuously as new measurements are made.

3.2. Min Measured Value

ID	Name	Type	Constraint	Quality	Default	Access	Conformance
0x0001	MinMeasuredValue	uint16	0 to  MaxMeasuredValue-1	X		R V	M

The MinMeasuredValue attribute indicates the minimum value of MeasuredValue that can be measured. The null value means this attribute is not defined. See Measured Value for more details.

3.3. Max Measured Value

ID	Name	Type	Constraint	Quality	Default	Access	Conformance
0x0002	MaxMeasuredValue	uint16	MinMeasuredValue+1 to 10000	X		R V	M

The MaxMeasuredValue attribute indicates the maximum value of MeasuredValue that can be measured. The null value means this attribute is not defined. See Measured Value for more details.

3.4. Tolerance

ID	Name	Type	Constraint	Quality	Default	Access	Conformance
0x0003	Tolerance	uint16	0 to 2048			R V	O

See Measured Value.

4. Measured Value

4.1. Constraint

Where MinMeasuredValue or MaxMeasuredValue attributes are mandatory the null value MAY be used to indicate that a limit is unknown.

For any measurement cluster with MeasuredValue, MinMeasuredValue and MaxMeasuredValue attributes, the following SHALL be always be true:

• If MinMeasuredValue and MaxMeasuredValue are both known, then MaxMeasuredValue SHALL be greater than MinMeasuredValue.
• If MaxMeasuredValue is known, then MeasuredValue SHALL be less than or equal to MaxMeasuredValue.
• If MinMeasuredValue is known, then MeasuredValue SHALL be greater than or equal to MinMeasuredValue.

4.2. Tolerance

For any measurement cluster with a MeasuredValue and Tolerance attribute, when Tolerance is implemented the following SHALL always be true:

• The Tolerance attribute SHALL indicate the magnitude of the possible error that is associated with MeasuredValue attribute, using the same units and resolution. The true value SHALL be in the range (MeasuredValue – Tolerance) to (MeasuredValue + Tolerance).
• If known, the true value SHALL never be outside the possible physical range. Some examples:
  • a temperature SHALL NOT be below absolute zero
  • a concentration SHALL NOT be negative