Introduction

The Coeus-WiFi/4G Wireless Temperature and Humidity Data Logger is a connected IoT monitoring system designed to record and transmit temperature and humidity data continuously. It is available in two communication versions: Coeus-WiFi for facilities with a stable wireless network, and Coeus-4G for remote, mobile or independent installations where a local WiFi connection is unavailable.

The logger is suitable for static and mobile applications, including cold rooms, refrigerators, freezers, pharmaceutical stores, vaccine rooms, laboratories, warehouses, food storage facilities, server rooms and other controlled environments. Live and historical records are available through the FreshLink mobile application and Freshliance Cloud platform.

How the Monitoring System Works

The built-in sensors measure environmental temperature and relative humidity according to the configured logging interval. Readings are stored locally and uploaded to the cloud through WiFi or 4G at the selected uploading interval. The large LCD displays the current values together with maximum and minimum records, battery status, time, date and connection information.

Users can configure the logger remotely, view device status, analyse graphs, manage alarm records and export reports. If the network connection is interrupted, recording continues in the device memory. The stored data synchronises automatically when the connection returns, maintaining a complete monitoring record.

WiFi and 4G Connectivity

Coeus-WiFi connects directly to a wireless router and does not require a SIM card or mobile-data plan. It is suitable for permanent indoor locations such as cold rooms, pharmacies, laboratories, server rooms and warehouses.

Coeus-4G sends monitoring data through a built-in cellular connection. It is ideal for remote facilities, mobile installations and applications where WiFi is unavailable or unreliable. The direct 4G connection supports remote setup, real-time tracking and alarm communication.

Optional External Probes

The logger can support up to two external probes. Available probe types include standard temperature probes, ultra-low-temperature probes, and combined temperature-and-humidity probes. These options extend the system from routine refrigerator monitoring to ultra-low-temperature applications reaching −90°C.

The standard probe cable length is 2 metres. Optional 5 m, 10 m, 15 m and 20 m cable lengths can be supplied for large cold rooms, specialised cabinets and installations where the logger must remain outside the monitored enclosure.

FreshLink and Cloud Platform

The FreshLink application and Freshliance Cloud platform provide dual remote access from mobile phones and computers. Users can check real-time measurements, historical data, device groups, alarm records and usage history without performing on-site manual checks.

Authorised users can configure supported devices, filter monitoring records, analyse trends and export data. This allows quality, maintenance and compliance teams to supervise multiple storage locations from a central platform.

Rechargeable Backup Battery

The logger uses USB Type-C charging and includes a 2600mAh rechargeable lithium battery. The backup battery maintains monitoring during a power interruption. Operating duration depends on the selected logging and uploading intervals; the product reference specifies up to 60 days at a 15-minute uploading interval, while longer upload intervals can extend standby performance.

Offline Recording and Data Continuity

Network loss does not stop data collection. During a WiFi or 4G outage, the logger continues to record readings in local memory. When the connection is restored, the missing records are uploaded automatically. This prevents avoidable gaps and maintains the integrity of the monitoring history.

Instant Local and Remote Alerts

High and low alarm limits can be configured for temperature and humidity. When a limit is exceeded, the logger provides local audible and visual warnings through the buzzer, display and indicator light. Remote alerts can be delivered through the FreshLink APP, email, SMS and the cloud platform.

This multi-channel alarm system helps responsible staff respond quickly to power failures, refrigerator faults, open doors, cooling-system problems and other conditions that may affect stored products.

Reports and Data Export

Monitoring records can be filtered by hour, day or week and exported for audits, quality investigations, compliance reviews and operational analysis. The system supports temporary report export while the logger remains active, allowing users to review data without ending the monitoring assignment.

Exported reports include temperature and humidity graphs, minimum and maximum values, alarm information and detailed data tables. PDF and CSV formats support both visual review and further spreadsheet analysis.