Overview

Product description

Efento NB-IoT loggers transmit the data over cellular networks (Narrowband IoT) and do not require any additional devices (router, gateway, etc.). Loggers are also equipped with Bluetooth Low Energy interface, which allows quick and easy configuration with a smartphone.

Loggers measure a number of parameters, including temperature, humidity, air pressure, soil moisture, state (open / close), number of pulses (pulse counters), air quality and various gases or water leakage.

Efento NB-IoT loggers communicate over CoAP protocol (RFC 7252) and can be integrated into any cloud platform or server based solution. Loggers can also work out of the box with the Efento Cloud platform. Devices can be fully managed remotely, including the remote configuration and secure software over the air (SoTA) updates.

Loggers are battery powered and can operate (depending on the signal quality and transmission interval) up to 10 years without any maintenance. In case of good signal quality (ECL = 0), the device is able to transmit the data up to 195 000 times.

Technical data

Cellular module	3GPP Release 13 Power 23 dBm NB-IoT bands: - 8, 20 (PCB antenna) - 1, 2, 3, 4, 5, 8, 12, 13, 17, 18, 19, 20, 25, 28, 66(u.fl antenna)
Battery	Battery pack 3.6V, 6300 mAh (up to 195 000 transmissions in ECL 0, lifetime up to 10 years)
Measured values	Each logger can have up to six slots. Each slot can measure one phisical value (e.g. temperature (internal sensor or probe), humidity (internal sensor or probe), air pressure, VOC, open/close, pulse counter, leakage)
Measurement and transmission intervals	Configurable by user Measurement interval: 1 minute – 10 days Transmission interval: 1 minute – 10 days
Memory	30 000 measurements If there is no network connection, the device buffers the measurements in its internal memory and transfers them to the platform once the connection is re-established. Once the memory is full, the oldest measurements are replaced with the new ones
Communication protocols	CoAP (RFC 7252), supports both confirmable and non-confirmable data frames Data is sent in Protocol buffers (protobuf) Bluetooth Low Energy (for communication with smartphones)
SIM card	Micro SIM (3FF) (default) Embedded SIM (available on request)
Network settings	APN (auto or manual) PLMN (auto or manual)
Indicators (troubleshooting)	LEDs singling the status of the device Device information, which can be requested by the server include: signal strength in dBm, total power in dBm, TX power in dBm, cell ID, ECL, SNR, EARFCN, PCI, RSRQ, total transmitted bytes, total received bytes, battery voltage, uptime Diagnostics data, including the network parameters and network connection status, is also available over Bluetooth
Mechanics	Enclosure material: ABS Size: 28 x 60 x 124 mm, 110 g Probes length (for loggers with probes only): by default 1 metre, other lengths are available on request Operating range: -35°C to +70°C Mounting: double side adhesive tape with acrylic glue or 2 x M3 screws
Certifications	CE, RoHS, FCC

Physical dimensions

Operating Modes

Power saving mode (PSM)

This is the mode of the reduced power consumption. The logger takes measurements with a period set by the user and saves them in its memory. Users can read the measurements and change the logger's settings using mobile devices with Efento mobile application installed. Device does not send / receive any data over the NB-IoT network.

Transmission mode

In this mode, the logger sends the data to a server / cloud platform over the NB-IoT network. During the transmission mode the logger consumes more power, but it only stays a few seconds in this mode. Devices can receive a new configuration in the response sent by the server. Devices enter the transmission mode for a few reasons, including the periodic transmission of data, user triggered transmission, transmission due to a threshold exceedance or retransmission.

In order to save energy, the logger remains in power saving mode most of the time. Communication with the server is initiated by the logger only for the purpose of sending data and (possibly) receiving a new configuration from the server.

LEDs

NB-IoT logger is equipped with two LEDs: green and red. If the device is on and works properly (device is in the Power Saving Mode), both LEDs are turned off all the time. Flashing of the diodes indicates the current status of the device or the action being performed by it. The LEDs are placed at the edge of the PCB and are visible through the cuts on the side of the logger housing. LEDs flashing indicate:

• Single blink of the red LED every 5 minutes - sensor has errors - it is either not able to register in the network or the data sent by the sensor does not reach the server

• Single blink of green LED every 5 minutes - sensor works properly

• Two blinks of the green LED - the device has taken a measurement

• Three blinks of the green LED - Transmission mode - data is sent over the NB-IoT network

• Red and green LEDs blink five times - Device starts up

• Fast blinking of the red LED - Device clears its internal memory (you can see it on the initial configuration of the device or when changing the measurement interval)