RTU RS232 TTL UART Modbus 4ChRelay Module
Product Information
Product Name: 4CH Modbus Relay Module
Work Voltage: DC 7V~24V
Load: AC 250V 10A or DC 30V 10A
Optocoupler Input Signal: DC 3.3V~24V
Set Address: 1~255
Interface: RS232/TTL UART
Control Channel: 4 channels
Baud Rate: 4800/9600/19600bps (Default
9600bps)
Weight: 92g
Size: 93*87mm
Product Usage Instructions
1. Opening Relay No. 1 (Manual Mode)
Send: FF 05 00 00 FF 00 99 E4
Return as is: FF 05 00 00 FF 00 99 E4
Remarks:
- The 3rd and 4th bytes of the sent frame represent the relay
address. The addresses of relay 1–relay 8 are 0x0000, 0x0001,
0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007. - The 5th and 6th bytes of the sent frame represent data. 0xFF00
represents opening the relay and 0x0000 represents closing the
relay.
FAQ
Q: What is the default baud rate for the module?
A: The default baud rate for the module is
9600bps.
Q: What is the work voltage range for the module?
A: The work voltage range for the module is DC
7V to 24V.
RTU RS232/TTL UART Modbus 4 Ch Relay
Module
Description:
1. Onboard mature and stable 8bit MCU and MAX3232 level conversion chip; 2. Communication protocol: support standard Modbus RTU protocol; 3. Communication interface: support RS232/TTL UART interface; 4. Communication baud rate 4800/9600/19200, default 9600bps, support power-off saving; 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-on, flash-off mode, flash-on/flash-off delay base is 0.1 S, the maximum flash-on/flash-off time can be set to 0xFFFF*0.1S=6553.5S; 7. Device address: range 1-255, default 255, support power-off saving; 8. Baud rate, input signal, relay status, device address can be read using software/commands; 9. Onboard 4-way 5V, 10A/250V AC 10A/30V DC relay, can be continuously closed 100,000 times, with diode discharge protection, short response time; 10. onboard relay switch indicator; 11. power supply voltage: DC7-24V,; 12. board size: 93*87mm, board weight: 92g;
Specifications: Product Name: 4CH Modbus Relay Module Work voltage: DC 7V~24V Load: AC 250V 10A or DC 30V 10A Ptocoupler Input Signal: DC 3.3V~24V Set address: 1~255 Interface: RS232/TTL UART Control channel: 4channel Baud Rate: 4800/9600/19600bps(Default 9600bps) Weight: 92g Size: 93*87mm
·1. Power input: DC7-24V power input terminal; ·2. Indicator: Four-way relay indicator and power indicator; ·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 negative ·4. RS232 communication interface; ·5. GND, RXD, TXD: TTL level UART communication interface, GND, RXD, TXD are connected to the GND, TXD, RXD of the external control end respectively, supporting the connection of 3.3V/5V external TTL serial port;
·6. RS232 and TTL serial port selection, when using RS232 communication, TI is connected to TXD and RO is connected to RXD; when using TTL communication, TI and RO are connected to the NC end. ·7. 4 independent relay switch signal outputs: NC: Normally closed terminal, short-circuited with COM before the relay is energized, and left floating after energization; COM: Common terminal; NO: Normally open terminal, left floating before the relay is energized, and left short-circuited with COM after energization.
Simple instructions for use: The Modbus relay module can receive Modbus RTU instructions from the host computer/MCU via the RS232/TTL UART interface to perform related operations. The following example uses the host computer software to open relays 1 and 2 (manual mode) through the RS232 interface. Assuming that the device address is 255 and the baud rate is 9600, the usage steps are as follows: ·1. Connect VCC and GND to 7-24V power supply; ·2. Connect the serial port to the serial port cable; ·3. Open the host computer software “ModbusRTU Configuration Tool 2” and 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” to turn on relay 1, and the indicator light of relay 1 will light up. As shown below:
Introduction to Modbus RTU instructions: Modbus devices perform related operations by receiving Modbus RTU instructions from an external control terminal (such as a host computer/MCU). A frame of instructions generally consists of a device address, function code, register address, register data, and a check code. The frame length is related to the function code. Generally, the first byte of each frame of data is the device address, which can be set in the range of 1-255, with the default of 255 (i.e. 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. Open relay No. 1 (manual mode) Send: FF 05 00 00 FF 00 99 E4 Return as is: FF 05 00 00 FF 00 99 E4 Remarks: The 3rd and 4th bytes of the sent frame represent the relay address. The addresses of relay 1–relay 8 are 0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007 (2) The 5th and 6th bytes of the sent frame represent data. 0xFF00 represents opening the relay and 0x0000 represents closing the relay
2. Close relay No. 1 (manual mode) Send: FF 05 00 00 00 00 D8 14 Return as is: FF 05 00 00 00 00 D8 14 3. open relay No. 2 (manual mode) Send: FF 05 00 01 FF 00 C8 24 Return as is: FF 05 00 01 FF 00 C8 24 4. close relay No. 2 (manual mode) Send: FF 05 00 01 00 00 89 D4 Return as is: FF 05 00 0100 00 89 D4 5. open all relays Send: FF 0F 00 00 00 08 01 FF 30 1D Return: FF 0F 00 00 00 08 41 D3 6. close 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 is: 00 10 00 00 00 01 02 00 01 6A 00 Remarks: The 9th byte 0x01 of the send 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 is: 00 10 00 00 00 01 02 00 FF EB 80 Remarks: The 9th byte 0xFF of the send frame is the written device address 9. Read the device address Send: 00 03 00 00 00 01 85 DB Return: 00 03 02 00 FF C5 C4 Remarks: The 5th byte of the return frame 0xFF is the device address read 10. read relay status Send: FF 01 00 00 00 08 28 12 Return: FF 01 01 01 A1 A0 Remarks: Bit 0-Bit 7 of the 4th byte 0x01 of the return frame represent relay 1-relay 8, 0 is closed, 1 is open 11. read the optocoupler input status Send: FF 02 00 00 00 08 6C 12 Return: FF 02 01 01 51 A0 Remarks: IN1-IN8 of the 4th byte 0x01 of the return frame represent the input signals of optocoupler 1-8, 0 represents low level, 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 Remarks: The 9th byte of the send frame is the baud rate setting value, 0x02, 0x03, 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 01C5 A7 14. Set the baud rate to 19200 Send: FF 10 03 E9 00 01 02 00 04 CA 0E Return: FF 10 03 E9 00 01 C5 A7 15. Read the baud rate Send: FF 03 03 E8 00 01 11 A4 Return: FF 03 02 00 04 90 53 Remarks: The 5th byte of the return frame represents the read baud rate, 0x02, 0x03, X04 represent 4800, 9600, 19200 respectively 16. Open relay No. 1 (flash mode 2S) Send: FF 10 00 03 00 02 04 00 04 00 14 C5 9F Return: FF 10 00 03 00 02 A4 16 Remarks: The 3rd-4th bytes of the sent 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 bytes of the sent frame represent the delay setting value. The delay base is 0.1S, so the delay time is 0x0014*0.1=20*0.1S= 2S, the relay will automatically close after opening for 2s 17. close relay No. 1 (flash mode 3S) Send: FF 10 00 03 00 02 04 00 02 00 1E A5 99 Return: FF 10 00 03 00 02 A416 Note: The 3rd and 4th bytes of the transmission frame represent the relay address. The addresses of relay 1 to relay 8 are 0x0003, 0x0008, 0x000D, 0x0012, 0x0017, 0x001C, 0x0021, 0x0026 (2) The 10th and 11th bytes of the transmission frame represent the delay setting value. The delay base is 0.1S, so the delay time is 0x001E*0.1=30*0. 1S=3S. The relay will automatically open after being closed for 3S.
Documents / Resources
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eBay RTU RS232 TTL UART Modbus 4ChRelay Module [pdf] User Guide RTU RS232 TTL UART Modbus 4ChRelay Module, RTU RS232, TTL UART Modbus 4ChRelay Module, Modbus 4ChRelay Module, 4ChRelay Module, Module |