Remote temperature sensor

 

Declaration of conformity

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Download the declaration of conformity

Presentation

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The Remote temperature  sensor is LoRaWAN class A sensor, it manages two different power supplies, one is external and may range from 9V to 24V, the other one is internal on the battery. It also integrates an internal antenna.

The sensor includes a 5 meters temperature probe.

The Remote temperature sensor allows the measure of temperature in a large set. It can mesure from -40°C to +90°C at a precision of 1°C.

The table below represents the precision of each temperature range:

Temperature range	Precision
[-40°C ; -34°C]	+/-1.5°C
[-33°C ; +9°C]	+/-1.0°C
[+10°C ; +37°C]	+/-0.5°C
[+38°C ; +64°C]	+/-1.0°C
[+65°C ; +82°C]	+/-1.5°C
[+83°C ; +90°C]	+/-2.0°C

The measure step is defined in the minimum field of a frame.

The housing is compatible with the following DIN rail adapter:

For more information about the casing, visit: www.spelsberg.com

Family code:

The family code of Remote temperature devices is: 50-70-043-xxx

Propagation radio

In order for the sensor to function correctly, it is better to limit the number of obstacles in order to avoid excessive attenuation of the radio wave, it is also important to put the sensor as high as possible. The cable gland should be positionned downward.

Autonomy

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The information in the table below represents how long the battery can last. It is  based on the default configuration at ambient temperature (+25°C) within the optimal use of the sensor throught LoRaWAN network (one uplink frame), and when  the spreading factor used is SF12.

The capacity of the disposable battery is 3.6Ah, 85% of it is used.

Transmission periodicity	Battery life
1 frame/ 2 hours	12 years

Human Machine Interface

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The Remote temperature sensor has a buzzer that allows it to “communicate” with the user.

After installing the device, switch ON the power to start-up the device.The buzzer rings until an association.

When the sensor is trying to associate to a network, it emits the following sound:

At the moment of association, the buzzer make the following sound:

A reed switch (or magnetic switch) is available. It is possible to use a magnet to activate it and make specific actions on the sensor (Switch off, switch on, Re-associtation…).

• Configuration: « void » frames are sent every minute for 10 minutes.

Standard reports are not functioning during this mode.

Configuration mode
Way to trigger it	One passage of the magnet near the reed switch or specific ZCL command
Way to stop it	Another passage of the magnet or specific ZCL command
Effects on the sensor
Time duration	The configuration mode lasts 10 minutes

• It is possible to ask a ReAssociation procedure if no down frame is received by the sensor during a given periodicity (4 days by default) or if a given number (100 by default) or failure (no acquittement is received) are reached by sending an applicative frame to the sensor or by the IHM of the sensor.

The sensor keeps the AppEUi and DevAddr configured, Confirmed/Unconfirmed  configuration and all applicative configurations. On the other hand, LoRaWAN configuration (channel, datarate …) are lost

ReAssociation Mode
Way to trigger it	Three passages of the magnet near the reed switch or ZCL command from LoRaWAN cluster.
Effects on the sensor

• A factory reset is available on nke Watteco’s sensors. It deletes all the applicative settings saved in the flash memory (i.e.: the configured batches and reports will be deleted).

The sensor keeps the AppEUi and DevAddr configured. On the other hand, LoRaWAN configurations (channel, datarate …) and applicative configurations are lost.

Factory reset
Way to trigger it	Two quick passages and a long passage of the magnet near the reed switch
Effects on the sensor

Applicative layer

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The Remote temperature sensor integrates the following clusters:

Cluster	Cluster name	Managed attributes
0x0000	Basic	All
0x0050	Configuration	All
0x8004	LoRaWAN	All
0x0402	Temperature Measurement	All

Default configuration

A default configuration is set:

• The device reports each 2 hours the temperature (EndPoint 0 / Cluster Temperature Measurement /Attribut Measuredvalue).

Every change on the default configuration must respect the legal duty cycle. (For example the most restrictive in EU is 0.1%, so in SF12 it is around 1 frame each hour)

Measurement periodicity

The measurement periodicity depends on the minimum, the maximum recording interval and the delta.

If the value of the minimum and the delta is 0, then the maximum value is the periodicity. However, if the value of delta is different than 0, then the periodicity is 1 second.

If the value of the minimum is different than 0, then this value is the same as the periodicity.

Frame examples

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Standard report

Report

 

Report of the temperature of the remote sensor

 

Configuration

 

Configure a standard report on the temperature

 

Batch report

• Configure a batch report on Temperature and Battery voltage:

Timestamp and record the temperature with a resolution of 1°C, a value has to be saved at least every 6 hours or on a variation of 1°C.

Timestamp and record all voltage power sources with a resolution of 0.2V, a value has to be saved at least all the 24 hours. All datas have to be concatenated and sent at maximum all the 24 hours.

→The solution to concatenate several different physical values in the same frame is to use the batch reporting. For the batch it is necessary to know the number of physical measure that will be sent to choose a label for each of them and the size of these labels. There are 2 kinds of power sources in the sensor (Rechargeable battery and Disposable battery). So, with the temperature and these 2 power sources, it is necessary to manage 3 different labels.

Number of label	Tag label	Tag size
1 or 2	0/1	1
3 or 4	00/01/11/10	2
5 or 6 or 7 or 8	000/001/010/011/100/101/110/111	3
...	...	...

The Tag Size to use for 3 labels is 2. Label 00 can be used for Temperature, Label 01 for level of Rechargeable Battery, and Label 10 for level of Disposable Battery. To configure the batch, it is necessary to send a command of “Configure reporting” at each cluster.

For temperature the delta has to be set to 100=0x0064 (1°C), minimum to 30=0x001e (30 seconds), the maximum to 6*60=360=0x8168 (6 hours), the resolution to 100=0x0064 (1°C) and the tag to 0b00000010=0x02 (size 2 and label 0). The cluster to report is 0x0402 and the attribut 0x0000 (MeasuredValue).

For Rechargeable Battery power sources the delta has to be set to 200=0x00c8 (0.2V), minimum to 10=0x800a (10 minutes), the maximum to 24*60=1440=0x85A0 (24 hours), the resolution to 200=0x00c8 (0.2V), the tag to 0b00001010=0x0a (size 2 and label 1), the field to 3=0x03. The same for Disposable Battery except the tag which has to be set to 0b00010010=0x12 (size 2 and label 2), and the field to 4=0x04. The cluster to report is 0x0050 and the attribut 0x0006 (Node power descriptor).

Power sources (Bits field)	Description
0x01	Constant (main) or External power
0x02	Rechargeable battery
0x04	Diposable battery
0x08	Solar harvesting
0x10	TIC harvesting
Others	Reserved
0x00	Undefined: should not occur

Applicative payload of the temperature

 

Applicative payload of the battery voltage

 

To decode the batch reception, use the br_uncompress. Type for Temperature is I16 (7) and for others the type is U16 (6), so it is necessary to use this command:

echo « 420500c0c04a0258b48fa08cef0a8ce10400100490ae215ab1b220b200 » | br_uncompress -a 2 0,100,7  1,200,6 2,200,6

Result

UNCOMPRESS SERIE

cnt: 2   # Counter of the batch (from 0 to 7)

845    # Timestamp in second of sending of the frame

# Format of data is: TimeStamp of Measure | Label | Value

811 0 2400    # TimeStamp: 811 s     Label 0: Temperature                   Value: 24°C

841 0 2600   # TimeStamp: 841 s     Label 0: Temperature                    Value: 26°C

844 2 0         # TimeStamp: 844 s     Label 2: Rechargeable battery        Value: 0 V

840 3 2700   # TimeStamp: 840 s      Label 3: Disposable battery            Value: 2.7V