Waveshare Industrial Modbus RTU 4-ch Relay Module with RS485 Interface, Industrial Grade Rail-Mount Case
The Modbus RTU 4-ch Relay Module is an industrial 4-ch relay module controlled via RS485 bus, utilizing Modbus RTU protocol. It features embedded protection circuits such as power isolation, ADI magnetically isolation, resettable fuse, and TVS diode, etc. It also comes with an ABS enclosure.
The Modbus RTU 4-ch Relay Module is very easy to use. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for industrial control equipment’s and/or applications with high communication requirement.
Features:
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Configurable device address (1~255), multi devices can be cascaded on RS485 bus
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Features flash-on, flash-off function, by passing arguments to the command, it is possible to turn on the relay for a while and then close it automatically
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Onboard voltage regulator, supports 7V~36V wide voltage supply
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Onboard unibody power supply isolation, provides stable isolated voltage, needs no extra power supply for the isolated terminal
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Onboard unibody ADI magnetical isolation, allows signal isolation, high reliability, strong anti-interference, low power consumption
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Onboard resettable fuse and TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, provides over-current/over-voltage proof, lightningproof & anti-electrostatic
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Onboard Optocoupler isolation, prevent the relay from being interfered by high-voltage circuit
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Adopts dedicated relay driver chip, with built-in flyback diode protection, for stronger and more stable driving ability
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Reverse-proof circuit, prevent the circuit from being damaged accidentally by incorrect connection
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High quality relay, contact rating: ≤30A 250V AC or ≤30A 28V DC
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Rail-mounted ABS plastic enclosure, easy to install, safe to use
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3 LEDs for indicating the MCU status and signal transceiving status
Specification:
Model: Relay Module No. of Channels: 4 Operating Voltage (VDC): 7~36 Communication Interface RS485 Contact Form: 1NO 1NC Contact Rating ≤30A 250V AC, ≤30A 28V DC Communication Protocol Standard Modbus RTU protocol
Package Includes:
1 x Modbus RTU Relay 4CH
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| Brand | WAVESHARE |
|---|---|
| Interface / Protocol | RS485 |
| SKU | AI7721 |
| Weight | 0.42 kg |
| Availability | In Stock |
Applications & Use Cases
The Waveshare Industrial Modbus RTU 4-ch Relay Module with RS485 Interface, Industrial Grade Rail-Mount Case is a versatile relay modules used across a wide range of applications including home automation, industrial control, IoT projects, Arduino/Raspberry Pi interfacing, and motor control.
Common use cases:
- Switching high-voltage AC appliances with a microcontroller
- Building a smart home relay board
- Automating irrigation pumps in agriculture
This product is ideal for electronics engineers, IoT developers, and automation hobbyists.
Technical Tip: Use optocoupler-isolated relay modules to protect your microcontroller. Match relay coil voltage to your MCU logic level (3.3V or 5V).
Shipping & Delivery
- Free shipping on orders above ₹999 across India
- Dispatched within 1-3 business days
- Expected delivery: 3-7 business days depending on location
- Secure packaging to ensure safe transit of electronic components
- Genuine WAVESHARE product sourced from authorized channels
Chirag Vyas (verified owner) –
Outstanding quality! This Waveshare Industrial Modbus RTU 4-ch Relay has been running 24/7 for months without a single failure.
Rashmi Dhillon (verified owner) –
Good quality Waveshare Industrial Modbus RTU 4-ch Relay. Using it for my college project. Performs as expected.
Rahul Garg (verified owner) –
Outstanding quality! This Waveshare Industrial Modbus RTU 4-ch Relay has been running 24/7 for months without a single failure.
Daksh Ghosh (verified owner) –
Great quality Waveshare Industrial Modbus RTU 4-ch Relay. All channels working. Optocoupler isolation is a nice feature.
Pranav Dubey –
Very satisfied. My smart home system runs on these Waveshare Industrial Modbus RTU 4-ch Relay modules. Totally reliable.
Dhruv Gupta (verified owner) –
Love this Waveshare Industrial Modbus RTU 4-ch Relay. Click sound is satisfying and switching is instantaneous.
Aman Rawat (verified owner) –
Excellent Waveshare Industrial Modbus RTU 4-ch Relay! Switching is clean and reliable. Using it for home automation.
Pranav Srivastava –
Average Waveshare Industrial Modbus RTU 4-ch Relay. Works but the relay generates some EMI. Added snubber to fix.
Ravi Negi –
Good Waveshare Industrial Modbus RTU 4-ch Relay. Works well. LED indicators are helpful for debugging.
Akash Vyas (verified owner) –
Good quality Waveshare Industrial Modbus RTU 4-ch Relay. Using it for my college project. Performs as expected.
Swati Pandey (verified owner) –
Good Waveshare Industrial Modbus RTU 4-ch Relay. Works well. LED indicators are helpful for debugging.
Dhruv Kohli (verified owner) –
Decent Waveshare Industrial Modbus RTU 4-ch Relay. Trigger voltage is compatible with both 3.3V and 5V logic.
Shubham Mishra (verified owner) –
Very satisfied. My smart home system runs on these Waveshare Industrial Modbus RTU 4-ch Relay modules. Totally reliable.
Ankit Bose –
Very satisfied. My smart home system runs on these Waveshare Industrial Modbus RTU 4-ch Relay modules. Totally reliable.
Prashant Bhandari (verified owner) –
This Waveshare Industrial Modbus RTU 4-ch Relay works perfectly with my Arduino. Easy to wire and control.
Isha Dhawan (verified owner) –
This Waveshare Industrial Modbus RTU 4-ch Relay is robust and well built. PCB quality is excellent.
Kapil Dhawan (verified owner) –
Great quality Waveshare Industrial Modbus RTU 4-ch Relay. All channels working. Optocoupler isolation is a nice feature.
Kritika Kamath –
Perfect Waveshare Industrial Modbus RTU 4-ch Relay for my IoT project. Controlling appliances remotely works flawlessly.
Shubham Solanki (verified owner) –
Good quality Waveshare Industrial Modbus RTU 4-ch Relay. Using it for my college project. Performs as expected.
Suresh Thakur (verified owner) –
Love this Waveshare Industrial Modbus RTU 4-ch Relay. Click sound is satisfying and switching is instantaneous.
Eshan Bisht –
Excellent Waveshare Industrial Modbus RTU 4-ch Relay! Switching is clean and reliable. Using it for home automation.
Arjun Deshpande –
Love this Waveshare Industrial Modbus RTU 4-ch Relay. Click sound is satisfying and switching is instantaneous.
Naveen Saxena (verified owner) –
Great Waveshare Industrial Modbus RTU 4-ch Relay. Easy to integrate with NodeMCU for WiFi-based control.
Sarthak Sharma (verified owner) –
Excellent Waveshare Industrial Modbus RTU 4-ch Relay! Switching is clean and reliable. Using it for home automation.