Elecbee Modbus RTU 8-Channel Relay Module RS485/TTL UART 8 Inputs 8 Outputs Switch Board for Industrial Smart Automation

SKU: EB0046370

Favorites

Key Features

Features:

Stable Hardware Core: Equipped with STM8S103K3T6 MCU and MAX485 level conversion chip, ensuring reliable communication and stable performance for long-term industrial or smart home automation tasks.
Dual Communication Interfaces: Supports standard Modbus RTU protocol with both RS485 (A+/B-) and TTL UART (TXD/RXD) interfaces, compatible with 5V TTL modules/MCUs and various control terminals for flexible integration.
8-Channel High-Load I/O: Features 8-channel DC3.3-30V optocoupler inputs (non-control) and 8-channel 10A/250VAC relay outputs (with diode protection), rated for 100,000 continuous activations—ideal for controlling motors, lights, or machinery.
Adjustable Configuration & Timing: Configurable baud rates (4800/9600/19200bps, default 9600, power-off saving) and device addresses (1-255, default 255, power-off saving). Supports manual, flash-off modes with 0.1S timing base (max 6553.5S delay) for precise control sequences.
Customizable for Advanced Projects: Includes an STM8 SWIM programming port for firmware customization, allowing users to adapt the module to unique automation needs. Powered by DC7-30V (5.08mm terminal) for versatile deployment in industrial, smart home, or security systems.

Specifications

Show Similar Products >

Attribute

Value

Wireless Capability

Bluetooth

Model

RS485

Show Similar Products >

Description

1. Onboard mature and stable STM8S103K3T6 MCU and MAX485 level conversion chip

2. Communication protocol: support standard Modbus RTU protocol

3. Communication interface: support TTL UART interface with RS485 / 5V level

4. Communication baud rate: 4800/9600/19200, default 9600bps, support to save after power off

5. The signal range of optocoupler input: DC3.3-30V (this input cannot be used for relay control)

6. Output signal: relay switch signal, support manual, flash off, flash off mode, flash off / flash delay base is 0.1S, maximum flash off / flash time can be set to OxFFFF * 0.1S = 6553.5S

7. Device address: range 1-255, default 255, support to save after power off

8. Baud rate, input signal, relay status, device address can be read using software / command

9. On-board 8-channel 5V, 10A / 250v AC, 10A / 30vDC relay, which can be continuously attracted 100,000 times, with diode bleed protection, short response time

10. Onboard relay switch indicator

11. STM8 SWIM program is reserved for programming, supporting customers to download their own firmware for secondary development

12. Power supply voltage: DC7-30V, 5.08mm terminal power supply

Manual: Click here to open

1 x Realy board

Modbus-RTU-Octal-Relay-Module-RS485--TTL-UART-8-Inputs-8-Outputs-Switch-Board-1685344

1. VCC, GND: DC7-30V 5.08mm power input terminal

2. DC3.3-30V optocoupler signal input:

IN1-IN8: Positive channel 1-8

GND_IN: Channel 1-8 common negative

3. A+, B-: RS485 communication interface, A +, B- are connected to A +, B- of external control terminal respectively

4. 5V, SWIM, GND, NRST: STM8 SWIM program download port

5. TXD, RXD, GND: TTL level UART communication interface, TXD, RXD, GND are connected to RXD, TXD, GND of the external control terminal, only support 5V level TTL module / MCU. Use wiring order suggestion: Modbus Power-Modbus module connects to TTL module-TTL module is powered on

6. RST: MCU reset button

7. Relay switch signal output:

NO: Normally open, the relay hangs before pull-in, short-circuit with COM after pull-in

COM: Common

NC: Normally closed end, the relay is short-circuited with COM before pull-in, and hangs up after pull-in

Modbus-RTU-Octal-Relay-Module-RS485--TTL-UART-8-Inputs-8-Outputs-Switch-Board-1685344

Shopping Guide

Shipping	Delivery Period	For in-stock parts, orders are estimated to ship out in 3 days. Elecbee ships orders once a day at about 5pm except Sunday. Once shipped, estimated delivery time depends on the below carriers you chose. DHL Express: 3-7 business days DHLeCommerce: 12-22 business days FedEx International Priority: 3-7 business days EMS: 10-15 business days Registered Air Mail: 15-30 business days
	Shipping Rates	Shipping rates for your order can be found in the shopping cart.
	Shipping Options	Shipping rates for your order can be found in the shopping cart.
	Shipping Tracking	We will notify you by email with tracking number once order is shipped. You can track your order using the “Track My Order” feature.
Returning/Warranty	Returning	Returns are normally accepted when completed within 30 days from date of shipment, please contact customer service for a return authorization. Parts should be unused and in original packaging. Customer has to take charge for the shipping
	Warranty	All Elecbee purchases come with a 30-day money-back return policy, plus 1-year Elecbee warranty against any manufacturing defects.
		This warranty shall not apply to any item where defects have been caused by improper customer assembly failure by customer to follow instructions, product modification, negligent or improper operation
Ordering	How to Buy	Elecbee accepts online orders.
		Add to cart > Check out > Submit order > Complete payment > Delivery
	Payment	PayPal, Credit Card includes Visa, Master, American Express, Bank transfer.