Transmission_&_Communication

{{company_name}}’s {{device_name}} transmits data collected from field sensors to the {{platform_name}} using secure wireless communication methods. To balance data availability, power consumption, and network reliability, the device uses scheduled transmissions, event-driven triggers, and configurable communication profiles.


Communication Technologies

{{device_name}} supports the following transmission methods:

  • Cellular (4G LTE, 3G, 2G fallback) – Default method for global deployments

  • LoRa (Long Range Radio) – For supported models using LoRa gateways or repeaters

Each communication method is configured in the {{platform_name}} or via the {{mobile_app}}.


Transmission Modes

Mode
Description

Scheduled

Sends stored samples at defined intervals (e.g., every 15 minutes)

Triggered (Threshold)

Sends data immediately when a defined threshold condition is met

Manual (via App)

Triggered manually using the {{mobile_app}} on-site

Always On

Continuous connectivity mode (used only in high-bandwidth, powered setups)


Scheduled Transmission

Scheduled transmission is the most power-efficient mode and ideal for battery-powered setups. It works by separating sampling from transmission:

  1. Data is sampled periodically based on configured SampleGroup intervals

  2. Sampled data is temporarily stored in the device’s internal SD card

  3. At the scheduled transmission interval, the device wakes up

  4. It packages the buffered data and transmits it to the {{platform_name}}

  5. The device then returns to low-power sleep mode

Although the SD card is non-volatile, it is not designed for permanent storage. Transmission to the {{platform_name}} ensures long-term retention and availability.

How to Configure:

  • Navigate to Device > Configuration > Communication in the {{platform_name}}

  • Set the desired Transmission Interval (e.g., 900 seconds for 15 min)

  • Save and synchronize settings


Triggered Transmission (Threshold-Based)

Triggered transmissions occur when sensor readings cross user-defined thresholds, prompting an immediate transmission outside the regular schedule.

How It Works:

  • Thresholds are configured in Stream Settings > Thresholds in the {{platform_name}}

  • Exceeding a high or low limit can:

    • Trigger a transmission

    • Generate an alert (email/SMS)

    • Do both, depending on configuration

Use Cases:

  • Sewer overflows

  • Battery or power dropouts

  • TBD: Security breaches or equipment faults


Manual Transmission (via {{mobile_app}})

Manual transmissions allow field technicians to validate system behavior on-site during installation or diagnostics.

How to Trigger:

  • Open the {{mobile_app}} and connect via Bluetooth

  • Tap "Sample Now" or "Transmit Now"

Manual transmissions can only be initiated via the {{mobile_app}} — not from the {{platform_name}} or API.


Cellular Connectivity Settings

For reliable network communication, you can configure:

  • Preferred network type (e.g., 4G only or 3G fallback)

  • Roaming preferences

  • SIM APN and credentials

  • Retry attempts and timeouts

Use the {{mobile_app}} to:

  • View real-time GSM signal strength

  • Test connectivity

  • Reboot the devivce if needed


Diagnostic Indicators

Use the built-in LED on the {{device_name}} to verify transmission and network status:

LED Status
Meaning

🟢 Solid green

Data transmitted successfully

🟢 Blinking green

Searching for network

🔴🟢 Alternating red/green

Communication failure

These LED behaviors are visible through the device’s housing and provide immediate visual feedback during installation, diagnostics, and routine operation.

Power Optimization Tips

  • Increase transmission intervals to conserve battery life

  • Avoid unnecessary threshold triggers if power usage is a concern

  • Use Always On mode only with external or solar power


Using "Always On" Mode

For applications that require frequent data communication, the Data Logger can be configured to operate in "always on" mode. This setting allows the device to maintain a constant communication channel with the server, reducing latency associated with connection establishment.

Firmware Requirement: This feature is available on firmware 2.40 and above.


When to Use "Always On"

Use "always on" mode if your application needs data transmission intervals of less than 5 minutes.

  • Pros:

    • Minimizes connection setup time

    • Enables faster data delivery

  • Considerations:

    • Increased power consumption

    • Reduced battery life

    • Potential service cost increase (consult your account manager)


Communication Channels Overview

The Data Logger utilizes two distinct channels:

HTTP

  • Used for sending commands and configurations between the server and the Data Logger.

MQTT

  • Used for transmitting sensor data from the Data Logger to the server.

By default, HTTP and MQTT share the same transmission interval, but they are independent channels.


Configuring MQTT Transmission Mode

Navigate to:

DEVICE ADVANCED CONFIGURATION --> GSM

Set the desired MQTT transmission mode:

Option
Description

PERIODIC

"Always on" is OFF

ALWAYS_ON

"Always on" is ON

ALWAYS_ON_WHILE_ON_EXT_POWER

MQTT stays on only when external power is connected. If power is lost, the session is closed and reopened at the next session time.


Additional MQTT Parameters

These advanced parameters fine-tune MQTT behavior:

  • mqtt_home_interval_minutes Home interval when "always on" is disabled or ext. power is unavailable.

  • mqtt_always_on_home_interval_minutes Home interval when MQTT is "always on".

  • mqtt_always_on_ping_interval_minutes Ping interval to keep session alive (default: 10 minutes, adjust per broker requirements).


HTTP and MQTT Interaction Notes

  • On an HTTP session, the MQTT connection is closed and reopened at the next scheduled MQTT session.

  • In "always on" mode, the modem remains active continuously → higher power usage.


Enabling/Disabling Communication

  • Disable HTTP: gsm_http_enable = 0

  • Disable MQTT: gsm_mqtt_enable = 0


HTTP Transmission Triggers

Regardless of MQTT state, HTTP will transmit if:

  • HTTP interval has passed

  • Device is in calibration mode

  • Last transmission failed

  • Event file exists

On every HTTP transmission, an MQTT transmission is also triggered.


Important

Enabling "always on" mode may increase service costs. Contact your account manager before enabling this feature.

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