Modbus RTU 4-way relay module 12V 4-way switch input optocoupler isolation RS485

Product Introduction

8-channel Modbus relay module
The 8-channel Modbus relay module is equipped with a mature and stable 8-bit MCU and RS485 level communication chip. Using standard MODBUS RTU format RS485 communication protocol, it can realize 8 input signal detection and 8 relay output, which can be used for digital quantity detection or power control occasions.

Product parameter
1. Onboard mature and stable STM8S103K3T6 MCU and MAX485 level conversion chip
2. Communication protocol: support standard Modbus RTU protocol
3. Communication interface: TTL UART interface supporting RS485/5V level
4. Communication baud rate: 4800/9600/19200, default 9600bps, support power-off save
5. Optocoupler input signal range: DC3.3-30V (this input cannot be used for relay control)
6. Output signal: relay switch signal, support manual, flash word, flash mode, flash off/flash
The base number of the interruption delay is 0.1S, and the maximum flash word/flash time can be set to OxFFFF*0.1S=6553.5S
7. Device address: range 1-255, default 255, support power-off save
8. Baud rate, input signal, relay status, device address can be read by software/command
9. There are 8 5V, 10A/250V AC 10A/30V DC relays onboard, which can be continuously closed for 10 times, with diode effusion protection, and short response time
10. On-board relay switch indicator
11. Reserve the STM8 SWIM program programming port to support customers' secondary development and download their own firmware
12. Power supply voltage: DC7-30V, using 5.08mm terminal power supply

Package Include:

1pc x 8-channel relay module

Modbus RTU Command

Suppose the device address is 0xFF so return 00 10 00 00 00 01 02 00 FF EB 80 and the 9th btye is the devices address.

Turn ON CH_1 Relay(Normal Mode)

• Send: FF 05 00 00 FF 00 99 E4
• Return: FF 05 00 00 FF 00 99 E4
• The 3rd and 4th byte are relay addresses. So it can be 0x0000,0x0001,0x0002,0x0003
• The 5th and 6th byte are relay data .0xFF00 means turn ON relay and 0x0000 means turn OFF relay

Turn OFF CH_1 Relay(Normal Mode)

• Send: FF 05 00 00 00 00 D8 14
• Return: FF 05 00 00 00 00 D8 14

Turn ON All relays

• Send: FF 0F 00 00 00 08 01 FF 30 1D
• Return: FF 0F 00 00 00 08 41 D3

Turn OFF All relays

• Send: FF 0F 00 00 00 08 01 00 70 5D
• Return: FF 0F 00 00 00 08 41 D3

Set device address to 0x01

• Send: 00 10 00 00 00 01 02 00 01 6A 00
• Return: 00 10 00 00 00 01 02 00 01 6A 00
• Note: The 9th btye is the device address

Set device address to 0xFF

• Send: 00 10 00 00 00 01 02 00 FF EB 80
• Return: 00 10 00 00 00 01 02 00 FF EB 80

Read device address

• Send: 00 03 00 00 00 01 85 DB
• Return: 00 03 02 00 FF C5 C4
• Note: The 5th btye is the device address

Read relay status

• Send: FF 01 00 00 00 08 28 12
• Return: FF 01 01 01 A1 A0
• Note: The 4th means which one relay.0 means OFF and 1 means ON

Read optocoupler input staturs

• Send: FF 02 00 00 00 08 6C 12
• Return: FF 02 01 01 51 A0
• Note: The 4th means which one input.0 means low level signal input and 1 means high level signal input

Set baud rate 4800bps

• Send: FF 10 03 E9 00 01 02 00 02 4A 0C
• Return: FF 10 03 E9 00 01 C5 A7
• Note: The 9th btye is baud rate value.0x02 is 4800bps.0x03 is 9600bps.0x04 is 19200bps

Set baud rate 9600bps

• Send: FF 10 03 E9 00 01 02 00 03 8B CC
• Return: FF 10 03 E9 00 01 C5 A7

Set baud rate 19200bps

• Send: FF 10 03 E9 00 01 02 00 04 CA 0E
• Return: FF 10 03 E9 00 01 C5 A7

Turn ON CH_1 Relay(2S Flashing Mode)

• Send: FF 10 00 03 00 02 04 00 04 00 14 C5 9F
• Return: FF 10 00 03 00 02 A4 16
• Note: The 3rd and 4th byte are relay addresses.So CH1~CH4 can be 0x0003,0x0008,0x000D,0x0012
  The 10th and 11th byte are delay time in second.The minimum delay time is 0.1s.Relay will OFF after delay time.So the delay time in this command is : 0x0014*0.1=2S

Turn OFF CH_1 Relay(3S Flashing Mode)

• Send: FF 10 00 03 00 02 04 00 02 00 1E A5 99
• Return: FF 10 00 03 00 02 A4 16
• Note: Relay will ON after delay time.So the delay time in this command is : 0x001E*0.1=3S