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3Wire RS2MQTT/RS2MQTT+ | 4G MQTT Gateway

3Wire Industrial 4G IoT Gateway

RS2MQTT / RS2MQTT+ Connect Field Devices to IoTWatt 4.0 Through 4G

3Wire RS2MQTT and RS2MQTT+ are industrial-grade 4G IoT gateways designed to connect serial and Ethernet-based field devices such as PLCs, power meters, sensors and controllers to cloud-based IoT platforms.

For IoTWatt 4.0 projects, RS2MQTT provides a practical cellular connectivity layer where LAN or WiFi is not available. It can poll Modbus RTU and DTL-645 data, convert selected parameters into JSON format, and transmit data using MQTT or HTTP POST over 2G / 4G GPRS / LTE networks.

2G / 4G Gateway MQTT HTTP POST RS232 / RS485 RS2MQTT+ Ethernet 800-Record Cache IoTWatt 4.0 Ready

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Product Type Industrial 4G IoT gateway for field-device data collection

Connectivity RS232 / RS485, 2G / 4G LTE, MQTT and HTTP POST

RS2MQTT+ Adds Ethernet port for TCP/IP-based data polling

IoTWatt Value Connects remote meters to IoTWatt 4.0 without site LAN dependency

Overview: Remote Field Data to Cloud Without Fixed Network

Industrial sites often need to collect data from power meters, PLCs, sensors and other field devices, but fixed network infrastructure may not be available at every location. This is common for remote pump rooms, substations, outdoor panels, branch sites, temporary monitoring points and multi-site energy monitoring projects.

RS2MQTT and RS2MQTT+ solve this by connecting field devices directly to IoT platforms through cellular networks. Data can be polled from connected devices and transmitted using MQTT or HTTP POST, allowing the same field data to support dashboards, alerts, reports, analytics and IoTWatt 4.0 digital energy audit workflows.

Key positioning

RS2MQTT is best positioned as an industrial 4G gateway for remote energy monitoring, multi-site IoT deployment, cellular Modbus data collection and IoTWatt 4.0 projects where LAN / WiFi is not practical.

How RS2MQTT Supports IoTWatt 4.0 Connectivity

IoTWatt 4.0 depends on reliable meter and equipment data. RS2MQTT enables remote sites and distributed assets to send data to the platform without requiring local LAN or WiFi infrastructure.

1. Field Devices Power meters, PLCs, sensors, controllers or DTL-645 meters.

2. RS2MQTT Polls serial data and prepares selected parameters.

3. Cellular Sends data over 2G / 4G GPRS / LTE network.

4. IoTWatt 4.0 Dashboards, tickets, analytics, reports and audit evidence.

5. Action Energy savings, EECA reports and operational visibility.

Model Selection

RS2MQTT

Designed for serial-based device connectivity using RS232 and RS485. Suitable for Modbus RTU meters, PLCs, controllers and sensors that communicate over serial protocols.

Best for: Remote serial meter data collection through 4G.

RS2MQTT+

Includes the serial communication features of RS2MQTT, plus an additional Ethernet port to support TCP/IP-based data polling.

Best for: Remote sites where both serial and Ethernet devices must be polled.

IoT Gateway Capabilities

2G / 4G Connectivity

Supports GPRS / LTE data transmission for cloud connectivity where fixed LAN or WiFi is not available.

MQTT

MQTT Protocol

Transmits field data to MQTT brokers and IoT platforms for monitoring, analytics and dashboards.

HTTP

HTTP POST

Sends collected data to cloud platforms through HTTP POST where MQTT is not used.

JSON

JSON Data Conversion

DTL-645 and Modbus RTU parameters can be polled and converted into JSON format.

800

Internal Cache Memory

Stores up to 800 data records to help reduce data loss during temporary cellular network disruption.

Watchdog Circuit

Dedicated watchdog circuit supports stable and continuous 4G connectivity operation.

Key Features

LTE

TDD-LTE, FDD-LTE and GSM

Supports three cellular modes for broad 2G / 4G network compatibility.

921

High Serial Baud Rate

Supports baud rates from 300 bps to 921600 bps with 5 to 8 data bits.

232

RS232 / RS485 Interface

Terminal block for RS485 and DB9 connector for RS232 serial devices.

RTU

Modbus RTU to Modbus TCP

Supports transparent serial transmission, Modbus RTU to Modbus TCP and MQTT protocol functions.

Up to 32 RS485 Slaves

Supports up to 32 slave devices connected on the RS485 bus, depending on site design.

200

Up to 200 Parameters

Can poll up to 200 parameters from connected serial devices for structured reporting.

AT Command Configuration

Supports serial port AT command configuration for device setup and control.

LED

LED Indicators

Power / 4G, Link and Active LED indicators provide local status visibility.

Heartbeat and Keep Alive

Heartbeat and Keep Alive functions help maintain reliable communication.

Technical Highlights

Parameter	RS2MQTT / RS2MQTT+ Specification
Product Type	Industrial-grade 4G IoT gateway
Models	RS2MQTT and RS2MQTT+
RS2MQTT+	Includes additional Ethernet port for TCP/IP-based data polling
Device Connection	Serial and Ethernet-based devices such as PLCs, meters and sensors
Cellular Modes	TDD-LTE, FDD-LTE and GSM
4G CAT 1 Bands	FDD LTE: B1 / B3 / B5 / B8; TDD LTE: B34 / B38 / B39 / B40 / B41; GSM: B3 / B8
Transmission Rate	LTE: 10 Mbps downlink / 5 Mbps uplink; GPRS: 85.6 Kbps downlink / 85.6 Kbps uplink
SIM Card	3V and 1.8V, standard SIM
Antenna	50Ω / SMA type
Serial Interface	RS485 terminal block and RS232 DB9
Serial Baud Rate	300 bps to 921600 bps
Data Bits	5 bits to 8 bits
Parity	None, Odd, Even, Mark and Space
Protocols	MQTT and HTTP POST
Modbus Function	Serial transparent transmission and Modbus RTU to Modbus TCP
JSON Conversion	DTL-645 and Modbus RTU parameters can be polled and converted to JSON format
RS485 Slave Capacity	Up to 32 slaves on RS485 bus
Parameter Polling	Up to 200 parameters polled
Cache Memory	Stores up to 800 data records
Configuration	Serial port configuration and 3Wire Device Management Software
Power Supply	9VDC to 48VDC, DC jack
Power Requirement	9-24V DC, 80mA @ 12V, 40mA @ 24V
Wiring	Plug-in screw terminal, accepts AWG12 to AWG30 wires
Operating Temperature	-40°C to +85°C
Storage Temperature	-45°C to +125°C
Humidity	5% to 95% RH
Dimensions	94mm (L) x 65mm (W) x 25mm (H)

Network deployment note

For cellular deployments, confirm SIM plan, APN settings, signal strength, antenna placement, data usage, MQTT / HTTP endpoint details and fallback behaviour before installation.

Typical Applications

IoTWatt 4.0 Remote Metering

Send remote Modbus meter data to IoTWatt 4.0 for dashboards, analytics and digital energy audit reports.

Multi-Site Energy Monitoring

Deploy across branches, distributed assets, pump rooms, substations, retail outlets or remote facilities.

PLC and Sensor Data

Send data from PLCs, meters and sensors to MQTT brokers, IoT cloud systems or monitoring dashboards.

Industrial IoT Retrofit

Enable cloud connectivity where existing serial devices need to be connected without major wiring changes.

Remote Utility Monitoring

Collect data from water, gas, power or process meters in locations without local network infrastructure.

Temporary Monitoring

Useful for temporary metering points where a permanent LAN / WiFi network is not available.

Integration with IoTWatt 4.0

RS2MQTT is useful in IoTWatt 4.0 Digital Energy Audit and Energy Intelligence projects where power meters or sensors are located at remote panels, branch sites or areas without reliable LAN / WiFi connectivity. It enables cellular data collection directly from the field.

IoTWatt 4.0 Use	How RS2MQTT Supports It
Remote Energy Dashboard	Publishes meter data through 4G to support IoTWatt 4.0 dashboards and site visibility.
Digital Energy Audit	Provides access to load profile and equipment data for audit evidence and analytics.
EECA Reporting	Supports remote meter data collection for regulatory reporting workflows.
Multi-Site Monitoring	Allows many sites to send structured data to a central IoTWatt 4.0 platform.
Data Continuity	Internal cache memory stores up to 800 records during temporary network disruption.

IoTWatt 4.0 call to action

Use RS2MQTT when energy data needs to be collected from remote panels, distributed assets or branch sites where LAN / WiFi is not available, but IoTWatt 4.0 dashboards, EECA reports and energy audit evidence are required.

Recommended Deployment Checklist

Confirm field device interface: RS232, RS485 or Ethernet for RS2MQTT+.
Confirm protocol type: Modbus RTU, DTL-645, Modbus TCP or transparent serial.
Confirm baud rate, parity, data bits, stop bits and slave address list.
Confirm SIM card type, APN, data plan and 2G / 4G network coverage.
Confirm antenna position and cellular signal strength at the installed panel.
Confirm MQTT broker or HTTP endpoint, topic structure, payload format and polling interval.
Confirm number of parameters to be polled and cache memory behaviour during network outage.
Test end-to-end communication before handover to IoTWatt 4.0 or the host platform.

Related Keywords

3Wire RS2MQTT 3Wire RS2MQTT+ 4G IoT Gateway Industrial MQTT Gateway Modbus RTU to MQTT Modbus RTU to JSON RS485 4G Gateway Remote Energy Metering IoTWatt 4.0 Ready Digital Energy Audit Connectivity EECA Meter Data Multi-Site Energy Monitoring

RS2MQTT Operation Diagram

The diagram below shows the RS2MQTT / RS2MQTT+ 4G IoT gateway operation concept, including field device polling, MQTT / HTTP transmission and cloud platform connectivity.

3Wire RS2MQTT and RS2MQTT+ industrial 4G IoT gateway operation diagram

RS2MQTT / RS2MQTT+ industrial 4G IoT gateway operation diagram

RS2MQTT Supply, Setup and IoTWatt 4.0 Integration

Saturn Pyro supports 3Wire RS2MQTT and RS2MQTT+ gateways for 4G remote meter communication, MQTT / HTTP publishing, RS485 / RS232 integration, Modbus data collection, IoTWatt 4.0 digital energy audit projects, EECA reporting data collection and multi-site energy monitoring in Malaysia.

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