Description

DC 7 -30V 8 Channel Modbus RTU Relay Module RS485 TTL UART Communication Board 8 Output Inputs for Arduino Power Control

Parameter:

Onboard mature and stable STM8S103K3T6 MCU and MAX485 level of conversion chip

Communication protocol: Modbus RTU protocol standard support

Communication interface: TTL UART interface support RS485 / 5V level

Communication baud rate: 4800/9600/19200, default 9600bps, support power-off save

Optocoupler input signal range: DC3.3-30V (this input cannot be used for the control relay)

Output signal: signal relay switch, support manual, word flash, flash mode, flash off / flash

The base number of the interrupt delay is 0.1S, and the maximum flash word / flash time can be set for OxFFFF * 0.1S = 6553.5S

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

Baud rate, input signal, relay status, device address can be read by software / command

8 onboard 5V, 10A / 250V AC 10A / 30V DC relay, which can be continuously closed for 10 times, with spill protection diode, and short response time

Relay on board indicator switch

STM8 SWIM stock port program programming to support secondary development and download their own customers firmware

Power supply voltage: DC 7-30V, with 5.08mm terminal power supply

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

2. DC 3.3 -30V optocoupler input signal:

IN1-IN8: channel 1-8 positive;

GND_IN: The negative pole of the common terminal of channels 1-8.

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

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

5. TXD, RXD, GND: TTL level communication interface UART, TXD, RXD, GND

Connect to RXD, TXD, GND of external control terminal respectively, And only support 5V level TTL module / MCU. Recommended wiring sequence: turn on the Modbus module & rarr; connect the Modbus module to the TTL module & rarr; Turn on the TTL module;

6. RST: MCU reset button

7. Signal output switch relay:

NO: end Normally open, the relay is suspended before closing, and shorted to COM after closing;

COM: public purpose;

NC: Normally closed, the relay is connected to COM before the pull-in, and is suspended after it is pulled-in.

Introduction for Modbus RTU instruction:

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

Assuming the device address is 255, 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

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

Notes: (1) The 3-4 bytes of the sending frame represent the relay address. The 1-relay 8 relay addresses are Ox0000, 0x0001,0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007

(2) The 5-6 bytes of the sending frame represent the data, 0xFF0O means opening the relay, and 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 No. 2 relays (manual mode)

Send: FF 05 00 01 FF 00 C8 24

Return as it is: FF 05 00 01 FF O0 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 DI 00 00 00 08 01 FF 30 1D

Return: FF DI 00 00 00 08 41 D3

6. Turn off all relays

Send: FF DI 00 00 00 08 01 00 70 5D

Return: FF DI 00 00 00 08 41 D3

7. Set the device address for 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

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

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

Notes: The 9th frame send byte, 0xFF, is the written address of the device

9. Read the device address

Send: 00 03 00 00 00 01 85 DB

Return: 00 03 02 00 FF C5 C4

Notes: The 5th byte of the return frame, 0xFF, is the address of the reading device

10. Read the relay status

Send: FF 01 00 00 00 08 28 12

Returns: FF 01 01 01 A1 AO

Notes: BitO-Bit7 of the 4th byte of the return frame, 0x01, represent relay 1 - relay 8, 0 means off, 1 means on

11. Read the optocoupler input status

Send: FF 02 00 00 00 08 6C 12

Returns: FF 02 01 01 51 AO

Notes: IN1 - IN8 of the 4th frame byte of the return 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

Return: FF 10 03 E9 00 01 C5 A7

Note: The 9th byte of frame send is the baud rate setting value, Ox02, 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

Return: 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 OE

Return: FF 10 03 E9 00 01 C5 A7

15, to read the transmission speed

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 of read, 0x02, 0x03, and x04 represent 4800, 9600, 19200, respectively,

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

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

Return: FF 10 00 03 00 02 A4 16

Notes: (1) The 3-4 bytes of the sending frame represent the relay address, the relay addresses 1-relay 8 are, respectively, Ox0003, 0x0008, 0x00OD, 0x0012, 0x0017, 0x001C, 0x0021,0x0026

(2) the 10th-11th byte of sending frame represents the delay setting value, the basic delay is 0.1S, so the delay time is 0x0014 * 0.1 = 20 * 0.1S = 2S, And the relay it will be turned off automatically after opening 2S

17, close the No. 1 relay (3S flash mode)

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

Return: FF 10 00 03 00 02 A4 16

Instructions for Use:

The Modbus relay module can receive ModbusRTU commands from the host computer / MCU via the RS485 / TTL UART interface to perform related operations. The following is an example of using the host computer software to open relay 1 and 8 (manual mode) through the RS485 interface. Assuming the device address is 255 and the baud rate is 9600, the steps are as follows:

1. Connect the VCC and GND of 5.08mm the power supply terminal;

2. A +, B- respectively USB A A + and B- of the RS485 output module;

3. Open the host computer software "ModbusRTU configuration tool", select the correct port number, select 9600 for the baud rate, set the address to 255, And click "open serial port";

4. Then click "JD1 open" and "JD8 open" to open relay 1 and 8, and the relay indicator lights at the same time.

Package Included:

1 * Modbus RTU 8 Channel RS485 TTL Serial Relay