Digital contact closure sensor ARF8420ABA

NB-IoTwirelessIoT

Overview
The DRY CONTACTS is an NB‑IoT / LTE‑Cat‑M1 On/Off (ON/OFF) connected sensor providing status and alarm feedback. It is designed to report binary states (0/1) and to support event counting and time‑in‑state measurements. The sensor is adaptable to many uses such as door opening detection, presence detection, machine start-up, alarms and similar binary status monitoring use cases.

Main functions

• Report 0‑1 states (binary status)
• Count events (increments counter each time the state changes)
• Measure and log time spent in a given state

Highlights of the IoT sensor

• Designed and manufactured in France
• Worldwide cellular compatibility (NB‑IoT and LTE‑Cat‑M1)
• Multi‑platform integration using LwM2M and MQTTS standards
• Up to 15 years of autonomy with standard configuration
• Two configurable digital inputs for 0/1 reading (Dry Contact) allowing connection to two independent sensors
• Configuration via NFC

Deploy simply and quickly

• Choice of connectivity on NB‑IoT or LTE‑M networks
• On‑site application parameterisation using NFC
• Automated provisioning on IoT platforms by bootstrapping (LwM2M)

Measure and alert as needed

• Remote supervision of simple binary data (open/close status: door contact, motion detector, smoke detector, gas detector, alarms, etc.)
• Event counter: records number of events and logs at configured frequency
• Time counter: measures time spent in a state and logs at configured frequency
• Transmission modes: periodic (status, events, time spent in a status) and event‑based (number of events and/or event duration)

Operate your fleet over the long term with LwM2M

• Standardized and remote device management operations, individually or in batches: commands, configuration read/write, FOTA (firmware over the air)

General characteristics

• Integrated mounting system: DIN rail, tube, wall, clamp
• Powered by 1 dual 8000 mAh battery pack
• Operating temperature range: -25°C to +70°C
• Enclosure protection: IP68

Technical features

• Periodic and/or event‑driven data transmission
• Local logging: optimized autonomy with local storage of 48 values per input
• Error / fault management: configuration error detection, low battery reporting
• Local data export via NFC

LwM2M / Security / Firmware update

• Compatibility with LwM2M 1.1 standard (over UDP)
• Data formats supported: SENML_JSON, TLV, CBOR, SENML_CBOR
• Bootstrap support
• Secure sensor/server communication via DTLS using PSK (Pre‑Shared Keys)
• Remote update of application firmware and modem firmware (FOTA)

Connectivity & SIM

• Cellular standard: 3GPP LTE Version 13
• Cellular IoT networks supported: NB‑IoT, LTE‑Cat‑M1
• SIM: Nano SIM 4FF | Class C (1.8V)

Certifications

• Directive 2014/53/EU (RED)
• US: FCC - Title 47 CFR Part 15
• Canada: RSS‑247 Issue 2
• AS/NZS 4268

Reference
Product reference: ARF8420ABA (DRY‑CONTACTS)

Technical specifications

• Dimensions: 200 x 63.5 x 34 mm
• Weight: 163 g
• Enclosure: IP68
• Mounting: DIN rail, tube, wall, clamp
• Power: 1 dual 8000 mAh battery pack
• Operating temperature: -25°C / +70°C
• Inputs: 2 configurable digital inputs (dry contact) for 0/1 state and two independent sensors
• Local storage: 48 values per input for optimized autonomy
• Transmission modes: periodic and event‑based (status, events, time spent)
• Configuration: NFC on‑site and remote configuration via LwM2M server
• Security: DTLS with PSK
• Firmware updates: remote FOTA for application and modem
• Data formats: SENML_JSON, TLV, CBOR, SENML_CBOR
• SIM: Nano SIM 4FF (Class C 1.8V)
• Cellular: 3GPP LTE v13 — NB‑IoT and LTE‑Cat‑M1
• Certifications: RED (2014/53/EU), FCC Part 15, Canada RSS‑247 Issue 2, AS/NZS 4268
• Reference: ARF8420ABA (DRY‑CONTACTS)