Waveshare
4-Channel Industrial Modbus RTU Relay Module – 30A, RS485, LED Indicators, Rail-Mount
· MPN: 30461
All Products
New Arrivals
Actuators
Brands and Manufacturers
Robotics & Motion
Sensors & Modules
Motor Drivers and Controllers
Sensors & Input
Industrial
Waveshare
$49.45
|
In stock
The Waveshare Modbus RTU 4-Channel Relay Module provides reliable high-current switching for industrial automation over an RS485 bus. Each of the four SPDT r...
Get notified when back in stock
Estimated Delivery
Arrives
Disclaimer
Secure checkout
The Waveshare Modbus RTU 4-Channel Relay Module provides reliable high-current switching for industrial automation over an RS485 bus. Each of the four SPDT relays handles loads up to 30A at 250VAC or 28VDC, making it suitable for controlling motors, lighting, HVAC systems, and other heavy-duty equipment.
Communication uses the standard Modbus RTU protocol with configurable device addresses (1–255), allowing multiple modules to be cascaded on a single RS485 bus. The module includes multi-isolation protection with ADI magnetic isolation, resettable fuse, and TVS diode to ensure stable operation in electrically noisy environments.
Key Features
- 30A High-Current Relays – 4× SPDT relays (1NO + 1NC each), rated ≤30A at 250VAC or ≤30A at 28VDC
- Standard Modbus RTU Protocol – Widely supported communication protocol for seamless integration with PLCs, HMIs, and SCADA systems
- Configurable RS485 Addressing – Set unique addresses from 1 to 255 for cascading multiple modules on one bus
- Multi-Isolation Protection – ADI magnetic isolation, resettable fuse, and TVS diode guard against electrical disturbances
- Wide Supply Voltage – Operates from 7V to 36V DC with built-in voltage regulation
- Automatic Flash Control – Program relays to turn on and off for a set period automatically
- LED Status Indicators – Monitor MCU status, data transmission, and reception at a glance
- DIN Rail Mounting – Industrial-grade ABS enclosure with rail-mount design for easy panel installation
Specifications
- Power Supply – 7–36V DC
- Standby Power – ~0.4W (all relays off at 12V)
- Active Power – ~4.9W (all relays on at 12V)
- Communication Interface – RS485
- Baud Rate Options – 4800, 9600, 19200, 38400, 57600, 115200, 128000, 256000 bps
- Default Format – 9600 bps, N, 8, 1
- Relay Channels – 4
- Contact Form – SPDT (1NO + 1NC per channel)
- Contact Rating – ≤30A 250VAC / ≤30A 28VDC
- Device Address Range – 1–255
- Protocol – Modbus RTU
- Dimensions – 145 × 90 × 40mm
- Weight – 278g
Ideal For
- Industrial automation and process control
- Building management and HVAC systems
- Home Assistant and smart home integration
- High-power machinery and lighting control
- PLC and SCADA system expansion
Package Contents
- 1× Modbus RTU 4-Channel Relay Module
Note: Power supply and RS485 converter are not included. An RS485-to-USB or RS485-to-TTL adapter is required to communicate with the module from a PC or microcontroller.
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- baud
- Baud is the signalling rate of a serial connection, often used as the speed setting for UART communication. Matching the baud rate matters because both connected devices must use the same setting for readable data.
- DC
- DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.
- DIN rail
- DIN rail is a standard metal mounting rail used inside industrial electrical cabinets. When a product is DIN rail mountable, it can be clipped neatly alongside power supplies, relays and other automation hardware in a panel.
- LED
- A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.
- microcontroller
- A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.
- Modbus
- Modbus is an industrial communication protocol used by many meters, sensors, PLCs and automation devices. When a product lists Modbus support, it is generally easier to integrate with existing industrial equipment that speaks the same protocol.
- Modbus RTU
- Modbus RTU is a version of the Modbus protocol that runs over serial wiring, commonly RS485. When a product lists Modbus RTU, it can connect to industrial sensors, meters or drives that use serial Modbus rather than Ethernet.
- Relay module
- A relay module uses an electrically controlled switch to let a low-power microcontroller control a separate circuit. It matters when switching devices that need different voltages or more current than a microcontroller pin can safely handle.
- RS485
- RS485 is a robust differential serial communication standard often used in factories, farms and buildings where cables may be long or electrically noisy, and it can link many devices on a single pair of wires. When a product lists RS485, it can communicate with industrial sensors, meters and control equipment over longer distances than typical hobby serial wiring.
- SCADA
- SCADA stands for Supervisory Control and Data Acquisition, a type of system used to monitor and control industrial processes from computers or control rooms. SCADA compatibility matters when a device needs to report to or take commands from such a larger central control or automation setup.
Find this product in
Robotics & Motion
Resources & Downloads
Guides, code examples, and more
Related Tutorials
Free guides on learn.littlebird.com.au
