Sentrius RS1xx LoRa-Enabled Sensors

It's important to note there are multiple RS1xx versions :

• Product Brief - Sentrius RS1xx Integrated Temp & Humidity Sensor
• Product Brief - Sentrius RS1xx External Temp Sensor
• Product Brief - Sentrius RS1xx with Open/Closed Sensor and Integrated Temp/RH
• Product Brief - Sentrius RS1xx External RTD Temp Probe (+180°C / +350°F) which is available with Low Temp RTD Probe and High Temp RTD probe

Those version and probes aren't interchangeable.

For instance, If you take an RS1xx External Temp Sensor, it won’t be equipped with humidity sensor.
In a same way, you won’t be able to use an RTD probe on an Ext Temp Sensor.

It's also good mentioning that all of External Temp and RTD Sensors will work correctly if and only if their temperature probes are connected and well tighten. You can refer to this guide for installation : User Guide - Sentrius RS1xx Ext. Temperature Sensors

Also, ensure that your RS1xx is loaded with the last firmware version. This can be uploaded using the Sentrius mobile application.

Last but not least, please make sure to check your RS1xx part number to confirm this is the version you think it is.

If non of the above work, please contact Laird Connectivity Support.

When should I replace the Rs186/RS191 batteries?

RS186/RS191 battery discharge is roughly linear up until 20%, at which point the batteries will start to discharge faster. It is recomended to replace the batteries ASAP after reaching 20% depending on the sensors duty cycle.

If your application provides battery notifications/flags then when the capacity reaches 20% would be a good time to push that notification.

While there is a direct correlation between the sensor reported battery capacity and battery voltage, the discharge curve is not completely linear.

Between 100% and 20% its essentially linear but below 20% the battery discharges faster.

Therefore a when the battery reports 50% capacity  it has more like 45% of its run time remaining.

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.

The RS186 has a SiLabs SI7021 sensor  integrated which comes with the following certificate of calibration;
https://www.silabs.com/documents/public/miscellaneous/si70xx-calibration-certificate.pdf

Laird Connectivity does not provide any additional calibration certification.

The Sentrius app, freely available on Android/iOS allows you to play with different scenarios in its battery life calculator/estimator without needing access to the hardware. Note that the range from the gateway in LoRaWAN impacts the datarate/spreading factor which in turn impacts the time on air for each packet which in turn impacts battery life. 
 

The latency of the RS1xx Sentrius LoRa sensor with external magnet open/close sensor is limited by the following reasons:

1) The RS1xx uses two internal dwell times to detect a door open and close. These can be set in the Sentrius smartphone app to a minimum of 5 seconds (which is also the default setting). So any state change faster than 5 seconds will be suppressed and a change or the open/close sensor state won't be transmitted faster than 5 seconds.

2) Independent of the dwell time the RS186 (EU868 region) faces a minimum LoRa uplink interval due to regulatory 1% duty cycle limitations of the 868MHz frequency band. At the maximum data rate (SF7BW125) the airtime is roughly 60msec, which then adds a dead time of 99x60msec=5.94sec. So from this we get a minimum cycle time of roughly 6 seconds. At the minimum data rate (SF12BW125) the airtime is roughly 1480msec plus a dead time of 99x1480msec=2.4min giving a minimum cycle time of roughly 2.5min.

So the latency of a door open/close state detection plus transmission for the RS186 would be 6 seconds at best case (maximum LoRa data rate SF7BW125) and 2.5min at worst case (minimum LoRa data rate SF12BW125).

The latency of the RS191 is not limited by duty cycle restrictions and hence end up at 5 seconds latency purely due to dwell time.

Yes, as long as they are operating on different networks such that AS923 sensors talk to the AS923 gateway and vice versa for AU915 devices. 

No, an RS1xx AS923 sensor will not work with an AU915 gateway because it cannot receive the downlink packets due to differing bandwidth and frequency plans used and therefore will drop off the network.

While the standard RS1xx (455-0001 for North America) can support down to -40°C and RS1xx external sensor (455-0070 for North America) can support down to -55 °C, typical AA batteries do not perform well at below -25 °C. Industrial grade of AA batteries may support lower temperature but they are significantly more expensive that off the shelf standard AA batteries. 

Laird Connectivity is committed to the long-term supply of all its standard embedded wireless modules and packaged products. Laird Connectivity’s products are specifically designed to meet the needs of the industrial and medical markets, which typically require 7 – 10 years product lifecycle. Although Laird Connectivity can’t guarantee that a component used in our products will not be obsoleted and cannot be reasonably substituted, Laird Connectivity can assure customers we will continue to sell our product when we have customer demand and can obtain the necessary components to build our products.

View our full policy here. 

The state change is based on ‘latency’;

1. The RS1xx uses two internal dwell times to detect a door open and close. These can be set to a minimum of 5 seconds (which is also the default setting). So anything faster than 5 seconds will be suppressed and a change or the door won't be transmitted faster than 5 seconds.
2. Independent of the dwell time the RS186 faces a minimum LoRa uplink interval due to duty cycle limitation. At the maximum data rate (SF7BW125) the airtime is roughly 60msec, which then adds a dead time of 99x60msec=5.94sec. So from this we get a minimum cycle time of roughly 6 seconds, hence smaller dwell times than 5 seconds wouldn't make much sense. At the minimum data rate (SF12BW125) the airtime is roughly 1480msec plus a dead time of 99x1480msec=2.4min giving a minimum cycle time of roughly 2.5min.

So the latency of a door open/closed state detection plus transmission would be 6 seconds in a best case scenario (maximum LoRa data rate SF7BW125).

This applies to the RS186 EU version due to duty cycle limitations.

The RS191 will end up at approximately 5 seconds latency, purely due to dwell time.