AC220V 4-Channel Relay Module Modbus RTU Support RS485/TTL UART Interface 9600bps For Digital Quantity Detection Power Control |

AC220V 4-Channel Relay Module Modbus RTU Support RS485/TTL UART Interface 9600bps For Digital Quantity Detection Power Control |

Features

1. On-board mature and stable 8bit MCU and MAX485 level conversion chip;

2, Communication protocol: support standard Modbus RTU protocol;

3. Communication interface: support RS485/TTL UART interface;

4. Communication baud rate: 4800/9600/19200, the default is 9600bps, and it supports power-off save;

5. Optocoupler input signal range: DC3.3-24V (this input cannot be used for relay control);

6. Output signal: relay switch signal, support manual, flash off, flash off mode, flash off/flash off delay base is 0.1S, the maximum flash off/flash off time can be set to 0xFFFF*0.1S=6553.5S;

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

8. The baud rate, input signal, relay status, and device address can be read using software/commands;

9. There are 4 onboard 5V, 10A/250V AC 10A/30V DC relays, which can be activated continuously for 100,000 times, have diode effusion protection, and have a short response time;

10. On-board relay switch indicator;

11. Power supply voltage: AC220V,

Interface introduction

1. Power input: AC 220V power input terminal;

2. Indicator lights: four relay indicator lights and power indicator lights;

3. DC3.3-24V optocoupler signal input:

IN1: Channel 1 positive

IN2: Channel 2 positive

IN3: Channel 3 positive

IN4: Channel 4 positive

GND_IN: Common terminal negative

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

5. GND, RXD, TXD: TTL level UART communication interface, GND, RXD, TXD are respectively connected to the GND, TXD, RXD of the external control terminal, and support the connection of 3.3V/5V external TTL serial ports;

6. RS485 and TTL serial port selection. When using RS485 communication, DI connects to TXD and RO connects to RXD; when using TTL communication, both DI and RO connect to the NC terminal.

7, 4 independent relay switch signal output:

NC,: normally closed, the relay is short-connected with COM before it is closed, and it is suspended after it is closed;

COM: public end;

NO: Normally open end, the relay is suspended before being closed, and shorted to COM after being closed.

Introduction to Modbus RTU instruction

Modbus devices perform related operations by receiving Modbus RTU instructions from an external control terminal (such as host computer/MCU). A frame of instructions generally consists of device address, function code, register address, register data, and check code. The frame length and Function code is related. Generally, the first byte of each frame of data is the device address, the range of which can be set is 1-255, the default is 255 (ie 0xFF), and the last 2 bytes are the CRC check code.

Assuming the device address is 255, the commonly used Modbus RTU commands are as follows:

1. Turn on relay No. 1 (manual mode)

Send: FF 05 00 00 FF 00 99 E4

Return as it is: FF 05 00 00 FF 00 99 E4

Remarks: (1) The 3-4 bytes of the sending frame represent the relay address. The addresses of relay 1-relay 8 are 0x0000, 0x0001,0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007

(2) The 5-6 bytes of the sending frame represent data, 0xFF00 means opening the relay, 0x0000 means closing the relay

2. Turn off the No. 1 relay (manual mode)

Send: FF 05 00 00 00 00 D8 14

Return as it is: FF 05 00 00 00 00 D8 14

3. Turn on the No. 2 relay (manual mode)

Send: FF 05 00 01 FF 00 C8 24

Return as it is: FF 05 00 01 FF 00 C8 24

4. Turn off the No. 2 relay (manual mode)

Send: FF 05 00 01 00 00 89 D4

Return as it is: FF 05 00 01 00 00 89 D4

5. Turn on all relays

Send: FF 0F 00 00 00 08 01 FF 30 1D

Return: FF 0F 00 00 00 08 41 D3

6. Turn off all relays

Send: FF 0F 00 00 00 08 01 00 70 5D

Return: FF 0F 00 00 00 08 41 D3

7. Set the device address to 1

Send: 00 10 00 00 00 01 02 00 01 6A 00

Return as it is: 00 10 00 00 00 01 02 00 01 6A 00

Remarks: The 9th byte 0x01 of the sending frame is the written device address

8. Set the device address to 255

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

Return as it is: 00 10 00 00 00 01 02 00 FF EB 80

Remarks: The 9th byte of the sending frame, 0xFF, is the written device address

9. Read the device address

Send: 00 03 00 00 00 01 85 DB

Returns: 00 03 02 00 FF C5 C4

Remarks: The 5th byte of the return frame, 0xFF, is the device address read

10. Read the relay status

Send: FF 01 00 00 00 08 28 12

Returns: FF 01 01 01 A1 A0

Remarks: Bit0--Bit7 of the 4th byte of the return frame 0x01 represent relay 1--relay 8, 0 is closed, 1 is open

11. Read optocoupler input status

Send: FF 02 00 00 00 08 6C 12

Returns: FF 02 01 01 51 A0

Remarks: IN1--IN8 of the 4th byte of the return frame 0x01 represents the input signal of optocoupler 1--optocoupler 8, 0 represents low level, and 1 represents high level

12. Set the baud rate to 4800

Send: FF 10 03 E9 00 01 02 00 02 4A 0C

Returns: FF 10 03 E9 00 01 C5 A7

Remarks: The 9th byte of the sent frame is the baud rate setting value, 0x02, 0x03, and x04 represent 4800, 9600, 19200 respectively

13. Set the baud rate to 9600

Send: FF 10 03 E9 00 01 02 00 03 8B CC

Returns: FF 10 03 E9 00 01 C5 A7

14. Set the baud rate to 19200

Send: FF 10 03 E9 00 01 02 00 04 CA 0E

Returns: FF 10 03 E9 00 01 C5 A7

15, read the baud rate

Send: FF 03 03 E8 00 01 11 A4

Returns: FF 03 02 00 04 90 53

Note: The 5th byte of the return frame represents the baud rate read, 0x02, 0x03, and x04 represent 4800, 9600, 19200 respectively

16, open the No. 1 relay (flash close mode 2S)

Send: FF 10 00 03 00 02 04 00 04 00 14 C5 9F

Returns: FF 10 00 03 00 02 A4 16

Remarks: (1) The 3-4 bytes of the sending frame represent the relay address, the addresses of relay 1-relay 8 are 0x0003, 0x0008, 0x000D, 0x0012, 0x0017, 0x001C, 0x0021,0x0026

(2) The 10th-11th byte of the sent frame represents the delay setting value, the delay base is 0.1S, so the delay time is 0x0014*0.1=20*0.1S=2S, and the relay is turned off automatically after 2S.

17. Turn off the No. 1 relay (flash mode 3S)

Send: FF 10 00 03 00 02 04 00 02 00 1E A5 99

Returns: FF 10 00 03 00 02 A4 16

Remarks: (1) The 3-4 bytes of the sending frame represent the relay address, the addresses of relay 1-relay 8 are 0x0003, 0x0008, 0x000D, 0x0012, 0x0017, 0x001C, 0x0021,0x0026

(2) The 10th-11th byte of the sent frame represents the delay setting value, the delay base is 0.1S, so the delay time is 0x001E*0.1=30*0.1S=3S, and the relay is turned off automatically after 3S