LoRaWAN Sensors

With the 1-Wire Digital Thermometer Probe, a connection problem at power up is indicated by both LEDs on the front panel being
constantly on. This is a visual indicator to the user that there is a communication issue between the sensor and the probe.

Please check the connector/plug of the external temperature probe for proper connection as well as its cable for mechanical damage.

LoRaWAN version: MAC V1.0.2
Regional Parameters version: PHY V1.0.2 REV B

‘Open Dwell Time’ and ‘Close Dwell Time’ are times for how long an Open or Closed state must be maintained before a change to that state is announced.

While the temperature sensor included in RS1xx supports accurate temperature measurements across an operating temperature from -40 to 125C, the type of batteries installed in RS1xx can be a limiting factor. If using normal AA Alkaline batteries that have a recommended range of -18 to 55C, it may not perform well at operating temperatures above 55C.

When the battery capacity indicator shows a value of 2 (out of 5), this should be taken as a warning and the battery should be replaced soon. Once the battery capacity indicator decreases to a value of 1, the batteries should be replaced immediately. 

The sensor will operate down to a capacity of a value of 0, but the time for the battery capacity indicator to decrease from a value of 1 to a value of 0 will be much quicker than the time it takes for the battery capacity indicator to decrease from a value of 4 to a value of 3, for example.

Note: As the battery nears depletion, it can be expected that LoRaWAN communications may be intermittent or fail. 

The Sentrius RS1xx backlog feature allows to store up until 4096 measurement in its flash memory that users can retrieve with either FIFO or LIFO mode. To enable this feature, you'll have to make sure of the following :

- Depending on how you want the backlog feature to operate (On Fail or Continious), choose either Laird or Laird2 packets format.

- Provide the RS1xx with the network time

The backlog feature only functions if the sensor has received a timestamp from the server. Every time a sensor will join the Network Server, it will ask to be provided with the network time. Please make sure the network provide its timestamp every time the sensor will request it as per Application Note - RS1xx LoRa Protocol, section 4.3 Server-to-Sensor Message : Set UTC Notification. 

More information on the RS1xx logging feature can be found into User Guide - Sentrius RS1xx Sensor Configuration section 8.9.

The Sentrius RS1xx LoRaWAN sensor has been designed to use as minimum power as possible to be able to run on batteries for years in the field. Class A has been naturally chosen to fulfil this aim as its the most power efficient class. The only downside of this will be on the downlink latency where messages from the network server will only be possible after an uplink from the sensor.

There is no way to enable Class B or C behaviour on the RS1xx sensor.

All Ezurio LoRa products should be referred as LoRaWAN as they all supports its protocol. LoRaWAN protocol make use of LoRa Chirp Spectrum Modulation within a license-free sub-gigahertz frequency band that allow to transmit regularly small packets up to 15km. 

It’s important to consider that 15km can only be achieved within absolute best conditions, some of which would be an outdoor “line of sight” transmission, interference free environment, ideal humidity/temperature, highest Spreading Factor, ect… Such range magnitude cannot represent any “real world” distance transmission and shouldn’t be expected by default.

The decision to switch between two LoRaWAN Class device is use-case specific and it needs to be initiated and proceed from both the end-device application layer and the LoRaWAN Network Server. It's good mentioning this process isn't managed at the LoRaWAN protocol level.

On the RM126x loaded with the AT Interface firmware, the Class device is configurable in the S Register 603 :

It is indeed possible to engage a Class change with AT Commands on the fly but once an S Register is changed, it must be followed by an AT&W to save the new configuration and then ATZ to reset the device. The Class device change will take effect once the RM126x will be reset so you'll have to re-join the LoRaWAN Network Server by issuing an AT+JOIN. It is advised to also engage in parallel the Class device change on the LoRaWAN Network Server and leverage the RM126x Join Sequence to apply the Class change on both sides.

LoRa Basics Modem (LBM) is an open-source LoRaWAN stack and software library that can run on external MCUs. It for example enables worldwide interoperability in the ISM sub-GHz and 2.4 GHz bands and is broadly used by many companies in their LoRaWAN end-node products.

Our AT Interface application and implementation for the RM126x series is utilizing the LoRa Basics Modem SDK version 2.0.1. It is developed and maintained by the Semtech Corporation and also publicly available on GitHub at https://github.com/Lora-net/SWSD001/tree/v2.0.1.