Industrial LoRaWAN DTU for RS485 & RS232 Serial Devices

RS485 / RS232 Serial Communication • LoRaWAN Wireless Transmission • Scheduled Data Polling • Conditional Reporting • Transparent Transmission • DIN-Rail Installation

The JW-D9L Series Industrial LoRaWAN DTU is designed to connect existing RS485 and RS232 field devices to LoRaWAN networks without replacing the original instruments.

It can actively poll connected serial devices at scheduled intervals, forward serial data transparently through LoRaWAN, report data according to predefined conditions, and receive remote configuration commands.

This makes the DTU suitable for industrial monitoring, smart agriculture, water monitoring, utility telemetry and other projects where conventional serial devices need to be integrated into a wireless IoT network.

1. Product Description

The JW-D9L Industrial LoRaWAN DTU is a serial-to-wireless communication terminal developed for industrial IoT projects using RS485 or RS232 devices.

Many field instruments, meters, controllers and sensors already communicate through RS485 or RS232. When a project is upgraded to a wireless architecture, replacing all existing devices may not be necessary.

The D9L DTU provides a communication bridge between these serial devices and a LoRaWAN network.

Instead of sending raw data through long-distance serial cables, the DTU can collect data locally and transmit it wirelessly to a LoRaWAN gateway.

This architecture is especially useful for distributed monitoring points where wiring is difficult, expensive or inconvenient.

2. How the LoRaWAN DTU Works

A typical system architecture can be configured as:

RS485 / RS232 Sensor or Instrument → JW-D9L LoRaWAN DTU → LoRaWAN Gateway → Network Server → Cloud Platform / SCADA / Third-Party System

The DTU communicates with the connected field device through its serial interface.

Depending on the project configuration, it can:

• poll the device at scheduled intervals
• transmit received serial data transparently
• trigger reporting based on data changes
• send heartbeat packets
• receive remote configuration or control commands

The LoRaWAN gateway then forwards the wireless data to the selected network server or application platform.

For a complete LoRaWAN field network, the DTU can be used together with JW-IoT communication products such as the Outdoor LoRaWAN Gateway available in the
Communication Devices product category.

3. Designed for Existing RS485 and RS232 Devices

One of the main applications of this DTU is upgrading existing serial equipment to a LoRaWAN network.

Many industrial sensors and controllers already use:

• RS485
• RS232
• serial polling
• customized communication protocols

Replacing these instruments only to obtain wireless connectivity may add unnecessary project cost.

The D9L series allows the original serial equipment to remain in service while adding LoRaWAN communication at the field node.

This makes it suitable for retrofit projects as well as new IoT installations.

4. Active Serial Data Polling

Unlike a simple serial radio converter, the DTU can be configured to actively poll connected RS485 or RS232 devices.

Polling commands can be issued according to a scheduled interval.

A typical process is:

Send serial command → receive device response → process or package data → transmit through LoRaWAN

This function can be useful when field instruments do not automatically transmit measurements and must be queried by an external master device.

Possible connected equipment may include compatible:

• industrial sensors
• environmental monitoring instruments
• meters
• controllers
• data acquisition equipment
• RS485 field devices
• RS232 instruments

The exact communication configuration should always be confirmed according to the protocol used by the connected device.

5. Conditional Data Reporting

The DTU supports conditional reporting based on changes between consecutive readings.

Instead of transmitting data continuously regardless of whether the reading has changed, the system can be configured to report according to the defined communication logic.

This type of reporting can help reduce unnecessary wireless traffic in monitoring applications where values remain relatively stable for long periods.

Actual reporting strategy should be selected according to:

• required sampling interval
• alarm response requirements
• LoRaWAN network capacity
• application server design
• field device communication protocol

6. Transparent RS232 / RS485 over LoRaWAN Transmission

The DTU supports transparent serial data transmission.

In this mode, serial data received from an RS232 or RS485 device can be forwarded through the LoRaWAN communication link without requiring the field device itself to support LoRaWAN.

This is useful for system integrators working with:

• legacy serial instruments
• proprietary serial protocols
• existing industrial equipment
• customized field devices

The DTU therefore acts as a communication interface between the serial device layer and the LoRaWAN network layer.

7. RS232 and RS485 Interfaces

The D9L series includes both serial interfaces.

The availability of both RS232 and RS485 makes the DTU suitable for projects containing different generations of industrial equipment.

8. LoRaWAN Communication

The DTU communicates through LoRaWAN and supports configurable radio parameters for different regional deployments.

Supported regional frequency options shown in the existing product specification include:

• EU433
• CN470
• CN779
• EU868
• AS923
• AU915
• KR920

The correct regional frequency band should be confirmed before ordering according to the LoRaWAN deployment country or region.

9. Remote Configuration and Heartbeat Communication

The DTU supports remote parameter configuration and command transmission.

This allows the communication logic to be adapted to different field devices and monitoring systems without changing the serial instrument itself.

Configurable functions can include:

• polling interval
• communication commands
• serial communication parameters
• user communication protocol
• heartbeat packets
• reporting logic

These functions are particularly useful in distributed deployments where multiple remote devices must follow a consistent communication strategy.

10. Industrial DIN-Rail Installation

The JW-D9L series is designed for 35 mm DIN-rail mounting.

This installation format is suitable for:

• industrial control cabinets
• automation panels
• telemetry cabinets
• monitoring enclosures
• equipment rooms

DIN-rail mounting allows the DTU to be installed together with PLCs, power supplies, relays, terminal blocks and other industrial control equipment.

For outdoor installations, the DTU should be installed inside a suitable protective enclosure according to the environmental requirements of the project.

11. Technical Specifications

12. D9L vs D9P

The main difference between the two versions is the maximum LoRa transmit power.

D9L

Maximum transmit power:

22 dBm

Suitable for standard LoRaWAN network deployments where the required link budget can be achieved with the local gateway layout.

D9P

Maximum transmit power:

27 dBm

Designed for configurations requiring higher radio output power, subject to applicable regional LoRaWAN and radio regulations.

Transmit power should not be selected based only on the maximum available value.

Gateway location, antenna installation, terrain, obstacles, regional radio regulations and spreading factor all influence actual LoRaWAN communication performance.

13. Typical Applications

Industrial Equipment Monitoring

RS485 and RS232 equipment installed inside factories or equipment rooms can be connected to the DTU for wireless transmission to a LoRaWAN network.

Typical use cases include:

• equipment status acquisition
• industrial sensor monitoring
• remote instrument data collection
• factory telemetry

Smart Agriculture

Agricultural projects often contain distributed sensors or controllers that already use RS485 communication.

The DTU can connect compatible serial devices to a LoRaWAN network for applications such as:

• greenhouse monitoring
• irrigation monitoring
• agricultural sensor networks
• remote equipment telemetry

Water and Environmental Monitoring

RS485 instruments are widely used in environmental and water monitoring projects.

A typical architecture can be:

Field Sensor → RS485 → LoRaWAN DTU → LoRaWAN Gateway → Monitoring Platform

The DTU can therefore be used as the communication layer for distributed water or environmental monitoring points.

Utility and Infrastructure Monitoring

The D9L can also be integrated into telemetry cabinets used in utility and infrastructure projects where serial equipment must transmit data wirelessly.

Applications may include:

• remote meters
• equipment rooms
• municipal monitoring
• distributed infrastructure
• remote telemetry nodes

14. When Should You Choose This LoRaWAN DTU?

The D9L series is especially suitable when:

• your existing equipment already has RS485 or RS232
• replacing the field device is unnecessary
• a LoRaWAN network is available or planned
• active serial polling is required
• transparent serial transmission is required
• the DTU will be installed inside a cabinet
• DIN-rail installation is preferred
• remote communication parameters need to be configurable

It is particularly useful for serial-device retrofit projects.

15. How Is It Different From a Battery-Powered LoRaWAN DTU?

JW-IoT provides different communication terminals for different installation conditions.

This DIN-rail D9L series is designed primarily for installations where external DC power and cabinet mounting are available.

For remote outdoor locations where battery operation and a weather-resistant enclosure are more important, a battery-powered LoRaWAN DTU may be more appropriate.

You can compare available communication devices in the
Communication Devices category.

This separation is important because power supply, enclosure requirements and installation environment often determine the correct DTU type.

16. LoRaWAN DTU vs LoRaWAN Gateway

A LoRaWAN DTU and a LoRaWAN gateway perform different functions.

LoRaWAN DTU

The DTU connects one or more compatible serial field devices to the LoRaWAN network.

It operates at the field-device side.

LoRaWAN Gateway

The gateway receives LoRaWAN wireless packets from field nodes and forwards them to a network server through an upstream network connection.

A typical architecture is therefore:

RS485 / RS232 Device → DTU → LoRaWAN Gateway → Network Server → Application

In most LoRaWAN monitoring systems, both field nodes and one or more gateways are required.

17. Accessories

Standard accessories shown for the existing product include:

• 1 × DTU main unit
• 1 × DC12V 1A power adapter
• 1 × LoRa antenna, blade or suction type

Accessories and antenna configuration should be confirmed according to the final project requirement.

18. Integration Considerations Before Ordering

To select and configure the correct DTU version, provide the following information:

1. Field device interface
RS485 or RS232?

2. Communication protocol
Modbus RTU or a customized serial protocol?

3. Baud rate and serial parameters
For example, baud rate, data bits, parity and stop bits.

4. Polling method
Does the DTU need to actively query the field device?

5. Required reporting interval
How frequently should data be transmitted?

6. LoRaWAN regional band
For example EU868, AS923 or AU915.

7. Network architecture
Existing LoRaWAN gateway or new gateway deployment?

8. Application platform
JW-IoT platform, private server or third-party platform?

Providing these details before configuration helps reduce integration work during field deployment.

Build Your RS485 / RS232 LoRaWAN Network

If your existing sensors, meters or controllers already use RS485 or RS232, you may not need to replace them when building a LoRaWAN monitoring network.

JW-IoT can help evaluate:

• serial device compatibility
• polling requirements
• LoRaWAN frequency selection
• DTU and gateway configuration
• field network architecture
• platform integration

Send us the model, serial protocol, baud rate and deployment region of your field device, and we can help determine the appropriate communication configuration.

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