Industrial Modbus RTU 8-Ch Relay Module With RS485 Interface

Overview

This is an industrial 8-ch relay module controlled via RS485 bus, utilizing Modbus RTU protocol. It features embedded protection circuits such as power isolation, ADI magnetical isolation, and TVS diode, etc. It also comes with an ABS enclosure.

The Modbus RTU Relay is very easy to use. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for industrial control equipments and/or applications with high communication requirement.

Features

• Configurable device address (1~255), multi devices can be cascaded on RS485 bus
• Features flash-on, flash-off function, by passing argument to the command, it is possible to turn on the relay for a while and then close it automatically
• Onboard unibody power supply isolation, provides stable isolated voltage, needs no extra power supply for the isolated terminal
• Onboard unibody ADI magnetical isolation, allows signal isolation, high reliability, strong anti-interference, low power consumption
• Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightning-proof & anti-electrostatic
• Onboard Optocoupler isolation, prevent the relay from being interfered by high-voltage circuit
• Reverse-proof circuit, prevent the circuit from being damaged accidentally by incorrect connection
• High quality relay, contact rating: ≤10A 250VAC/30VDC
• Rail-mounted ABS plastic enclosure, easy to install, safe to use
• 3 LEDs for indicating the MCU status and signal transceiving status

Specifications

• Power supply voltage: 5V
• Communication interface: RS485
• Baudrate: 4800, 9600, 19200, 38400, 57600, 115200, 128000, 256000
• Default communication format: 9600, N, 8, 1
• Relay channels: 8
• Contact form: 1NO 1NC
• Communication protocol: Standard Modbus RTU protocol
• RS485 address: 1~255
• RS485 terminal protection: 600W lightning-proof and surge-suppress, 15KV ESD protection (reserved 120R balancing resistor solder pads)
• LED indicators:
  
  • STA: MCU indicator, keep flashing when the MCU normally working
  • TXD: TX indicator, light up when sending data
  • RXD: RX indicator, light up when receiving data

RS485 8-Ch Relay Module

Modbus RTU Protocol, Multi Isolation Protection Circuits, Safe & Stable & Reliable

Hardware Analysis

Enclosure Design

Rail-Mounted ABS Plastic Enclosure, Easy To Install, Safe To Use

RS485 Communication

Configurable Device Address (1~255), Multi Devices Can Be Cascaded On RS485 Bus

In Case Of Many Devices Are Cascaded, Or Communication Distance Is Quite Long, It Is Necessary To Use RS485 Repeaters

Relay Connection

Contact Rating Of The Onboard Relay Up To 10A 250VAC/30VDC
Directly Controlling 220VAC Home Appliances, Or Devices Below 30VDC

Outline Dimensions

Development Resources

Wiki : www.waveshare.com/wiki/Modbus_RTU_Relay

Package Content

• Modbus RTU Relay x1
• Power adapter US plug 5V/2A 5.5/2.1 x1
• Power adapter EU head x1

FAQs:

Q: What are the main features of the Industrial Modbus RTU 8-Channel Relay Module?

A: The module features 8 isolated relay channels controlled via Modbus RTU over an RS485 interface. It offers reliable switching for various devices and applications in industrial automation systems.

Q: What is Modbus RTU and how does it work with this relay module?

A: Modbus RTU is a serial communication protocol used for industrial automation. This relay module uses Modbus RTU over RS485 to allow remote control of the relays through a Modbus-compatible device or software.

Q: What is the maximum switching current for the relays on this module?

A: Each relay on the module can handle a maximum switching current of 10A at 250V AC or 30V DC, making it suitable for controlling high-power devices and equipment.

Q: What is the RS485 communication range for the Industrial Modbus RTU Relay Module?

A: The RS485 communication range for the module can reach up to 1200 meters (approximately 4000 feet) at 9600 bps, depending on the quality of the RS485 network and cable used.

Q: How do you configure the Modbus RTU settings for the 8-Channel Relay Module?

A: The Modbus RTU settings, including the device address and baud rate, are configured using DIP switches on the module. The user manual provides detailed instructions on setting these parameters for proper operation.

Q: What type of power supply is required for the relay module?

A: The module requires a 12V DC power supply to operate. Ensure that the power supply provides sufficient current for both the module and the devices being controlled.

Q: Can the relay module be used in outdoor environments?

A: This relay module is designed for industrial environments but is not specifically rated for outdoor use. For outdoor applications, ensure proper enclosures and protection from environmental factors.

Q: How do you connect the RS485 communication lines?

A: RS485 communication lines are connected to the A and B terminals on the module. Follow the pinout and wiring instructions provided in the user manual for proper connection to your Modbus RTU network.