Overview

• This product is an industrial grade dual Ethernet ports controlled 8-ch relay module with 8-channel digital inputs, adopts Modbus RTU/Modbus TCP protocols, supports PoE power supply, also comes with ABS housing design. This relay module is very easy to use. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for industrial control equipments and/or applications with high communication requirements.

Electrical Safety Precautions

• This product should be operated and used by professional electricians or technical personnel. During use, please ensure electrical safety and take protective measures such as anti-leakage and insulation.
• Before installing, maintaining, or replacing relay equipment, make sure to turn off the power and unplug the device.
• Do not attempt to dismantle relay equipment to avoid damaging the device or risking electric shock.
• Please properly install and place the relay equipment. Avoid using it in damp, overly hot, or flammable environments to prevent safety accidents due to improper installation or use.

Specifications

Indicator Light Description

Primary Functions

Supports reading digital input by sending Modbus RTU protocol commands via Ethernet, and can control relay output based on input.

Wiring Description

• Connect the module to the LAN via a network cable, and supply power through 7~36V power port or the POE. Both Ethernet ports are functionally the same and can be used for network port communication and cascading.
  

DI1-DI8 are the 8-channel signal input terminals, and DGND is the signal terminal ground. COM is the common terminal for the input signal, it can be NC (Not Connected), connected to the positive or negative poles of the power supply, directly powered from the power supply or connected to an independent power supply.

• COM not connected: dry contact passive input

• COM connected to the positive pole of power supply: low active, NPN wet contact active input, voltage: 5V-30V DC
• COM connected to the negative pole of power supply: high active, PNP wet contact active input
  

PNP Digital Input 

Operation Modes Introduction

The relay supports multiple control modes, and each channel supports independent setting of control modes</ p>

• Note: The output of the linkage mode is only controlled by the input and does not respond to the command. Except for the Linkage Control, other modes support controlling relays via commands.

Module Parameter Configuration

The module needs to set the module parameters before communication, such as IP address, serial port format, Modbus protocol, etc. There are two modes of setting parameters: Vircom software configuration and web configuration.
Vircom software configuration allows for setting more parameters, but requires software installation. Web configuration does not require installation, but you need to know the IP address first, and the configuration parameters are few. It is recommended to use Virom for configuration.
Note:
1. The configuration can be done in any way, and it is recommended to use Virom software for first test.
2. It is recommended to modify only the IP address for the first configuration, other parameters are not recommended to be modified. The serial port parameters must be the default parameters; modifying the serial port parameters will result in no communication.
3. The module supports both Modbus RTU and Modbus TCP protocols. In the Advanced Settings -> Transfer Protocol, you can choose "None", which means the Modbus RTU protocol. It is not recommended to modify during the first configuration.
4. The selected Modbus TCP protocol must be configured using the Virom software and set to a non-storage Modbus gateway, otherwise the communication will not be normal.

Virom Software Mode Configuration

General Settings

Connect the module to the hardware and connect it to the network. Run the VirCom software (the computer on which Vircom is installed must be on the same LAN as the module).
The operation is as follows:

• ① Click Device
• ② Click Auto Search
• ③ The software searches for and identifies devices connected to the LAN
• ④ Select the device, and then click Edit Device or double-click the searched device directly
• ⑤ Set the working parameters of the device:
  • Click the "Local IP" button to identify the IP address of the computer, modify the "IP address" to a static assigned address, and note that the static IP address entered is not used by other devices, and it needs to be on the same LAN as the computer.
    
  • The working mode is TCP server. The serial port setting is 115200 by default and cannot be modified.
    
  • The "Transfer Protocol" in "Advanced Settings" defaults to "None", which means using the Modbus RTU protocol; if you select "Modbus TCP protocol", then use the Modbus TCP protocol for communication.
• ⑥ Once the settings are complete, click Modify Setting
• ⑦ Click Restart Dev, wait for the module to restart, and the new settings will take effect.

Note: It is recommended to modify only the IP address for the first configuration, and do not modify other parameters.
See the figure below for details:

Protocol Setting

Note: It is recommended to use the default Modbus RTU protocol for the first configuration and no modifications are needed.
Although the module transmits data through the network port, it supports two Modbus protocols: Modbus RTU and Modbus TCP. By default, data is transparently transmitted, i.e. using the Modbus RTU protocol.
The "Transfer Protocol" in the "Advanced Settings" can be set to Modbus TCP protocol. In this case, the Modbus RTU protocol of the main controller will be converted to the Modbus TCP protocol and transmitted through the network port.
In this case, the device port automatically changes to 502. Users can connect their Modbus TCP tool to the IP of the serial port server on port 502.

• If set to Modbus TCP protocol, it also needs to be set to a non-storage Modbus network port. Click on "More Advanced Settings..." and select the Modbus Gateway Type as a non-storage Modbus gateway.

Note: The default Modbus gateway type is storage type, which will automatically send query commands several times, which may cause the controller chip not to respond, and the query commands will not be affected. Therefore, you need to set it as Multi-host non-storage type. 

Virtual Serial Port Setting

The module transmits data through a network port (TCP/UDP protocol). In order to enable users to communicate even with developed serial port software, a virtual serial port needs to be added. If not needed, this part can be skipped.
First, install the virtual serial driver Virtual serial port driver, and run Vircom and the user program on the same computer.
Vircom virtualizes a COM port that corresponds to the serial port server. When the user program opens the COM communication, it can send data to the user's serial port device through the Vircom serial port server. The following steps demonstrate this operation:
Click on "Serial Port & Device Management" on the Vircom main interface, then click "Add" and select to add COM2 (Among them, COM2 is the newly emerging COM port on the computer).

• Then enter the device management and double-click the device that needs to be bound to COM2. As shown in the diagram, select COM2 from the Virtual Serial Port list in the top left corner. Then click on "Modify Setting" and then click on "Restart Device".

• Return to the main interface of Vircom. It can be seen that COM2 has been connected to the device whose IP is 192.168.1.200. In this case, the virtual serial port COM2 can be used instead of the network port for communication.
  

WEB Configuration

Using Vircom, you can search for and configure device parameters in different network segments. For Web configuration, you must first ensure that the computer and the serial server are in the same IP segment, and you need to know the IP address of the serial server in advance.
But Web configuration can be done on any computer without Vircom. (Different products have different web interfaces, which can be switched between Chinese and English)
1. Enter the IP address of the serial server in the browser, such as http://192.168.1.200 to open the following web page

2. Enter password in "Password": There is no login password set by default in the factory, you can enter a password at will, and click the Login button to log in. After setting the password to log in, the settings at "Modify Web Login Key" will take effect:

3. The serial server parameters can be modified on the web page that appears.
4. After modifying the parameters, click the "Submit" button.
Attention: The system has added webpage settings function by default when it leaves the factory. If the configuration interface page file is overwritten and the webpage cannot be opened, the webpage file needs to be downloaded again.
Please refer to RS485 TO ETH (B) Manual

Example Demonstration

The demo shows how the following two software operate.
SSCOM serial port debugging assistant is more convenient to operate, free of installation, and more convenient for complete display and analysis of instructions, but the disadvantage is that the data is not intuitive.
Modbus Poll software is directly operated on the register, and the data display is more convenient to observe, but the disadvantage is that the instruction is not displayed completely, so you need to be familiar with the Modbus register operation.
You can test using any method. It is recommended to use the SSCOM serial port debugging assistant software for the first test.

SSCOM Serial Port Debugging Assistant

• Open the serial debugging assistant window, select TCPClient for the port number, modify the remote IP and port number according to the above Vircom settings, select ModbusCRC16 if you need to add the check. Click the "Connect" button to connect to the TCP server, the green light of the network port will light up after successful connection.
  
  

Click Multi-Char to open the Send Multi-Char window, the default display is the Modbus RTU command, and there is no CRC check, select ModbusCRC16 if you need to add the check. Click on the function to send the corresponding command.
Note: The module defaults to normal mode at the factory, the relay can be directly commanded and controlled. If there is a command to return normally, but the relay does not act, the module may have been changed to other control mode, you can query it by reading the relay control mode command.

• The default configuration is Modbus RTU command. If set to Modbus TCP command, the command needs to be changed. *Click on the Import ini button in the Send Multi-Char column, and select the Modbus tcp.ini file to import.
  

If the error "A component named HEX0 already exists" is displayed, close the software and reopen it, then re-import the file.

• After successful import, the following is displayed, click on the function to send the corresponding command.
  

Note: Modbus tcp does not require CRC checksum, select None for checksum.

• For detailed Modubs commands, please see the development protocol.

Modbus Poll Software

• The serial port software is not convenient to observe the data, you can choose Modbus Poll software to read the data. Download and install the Modbus Poll software.
• Open the software, select Setup->Read/Write Definition, select the actual device address for Slave ID, select 01 Read Coils function code for Function, and change Quantity to 8 channels. Click OK to confirm.

• Select Connection ->Connect..., select the connection method for Connection.
  

If configured as Modbus RTU command, select Modbus RTU/ASCII Over TCP/IP, select the Mode as RTU. If configured as Modbus TCP command, select Modbus TCP/IP.
Enter the correct IP address and port number. Click OK to connect.

• After the connection is normal, you can check the current relay status. Select the corresponding channel, then double-click the status value to pop up the send page. Choose On or Off, then Click Send to control the relay opening and closing.

• Choose File->New to create a new window, select Setup->Read/Write Definition, choose the actual device address for Slave ID, select 02 for Function, set Address to 0, set Quantity to 8 channels, and change the Scan Rate to 100ms. Click OK to confirm.

• The new window 2 can display the current input status, change the input interface level, and the corresponding values will also change.

Demo

Raspberry Pi

Connect the Raspberry Pi and the ModBus POE ETH Relay module to the same LAN.
Open the Raspberry Pi terminal and run the program by entering the following command.
After the demo normally runs, each channel can be opened and closed sequentially, and finally the current input status is displayed.

sudo apt-get install unzip
wget https://files.waveshare.com/wiki/Modbus%20POE%20ETH%20Relay/Modbus_POE_ETH_Relay_B_Code.zip
unzip Modbus_POE_ETH_Relay_B_Code.zip
cd Modbus_POE_ETH_Relay_B_Code

#modbus rtu protocol
vi modbus_rtu.py  #Change the IP address and port number according to the actual situation
sudo python3 modbus_rtu.py

#modbus tcp protocol
vi modbus_tcp.py  #Change the IP address and port number according to the actual situation
sudo python3 modbus_tcp.py

Note: To run this demo, you need to modify the demo file to change the IP address and port number to the actual IP address and port number of the ModBus POE ETH Relay.

Development Protocol V2

Relay 0 on: 01 05 00 00 FF 00 8C 3A
Relay 0 off: 01 05 00 00 00 00 CD CA
Relay 1 on: 01 05 00 01 FF 00 DD FA
Relay 1 off: 01 05 00 01 00 00 9C 0A
Relay 2 on: 01 05 00 02 FF 00 2D FA
Relay 2 off: 01 05 00 02 00 00 6C 0A
Relay 3 on: 01 05 00 03 FF 00 7C 3A
Relay 3 off: 01 05 00 03 00 00 3D CA
Relay 0 toggle: 01 05 00 00 55 00 F2 9A
Relay 1 toggle: 01 05 00 01 55 00 A3 5A
Relay 2 toggle: 01 05 00 02 55 00 53 5A
Relay 3 toggle: 01 05 00 03 55 00 02 9A

All relays on: 01 05 00 FF FF 00 BC 0A
All relays off: 01 05 00 FF 00 00 FD FA
All relays toggle: 01 05 00 FF 55 00 C2 AA

Send: 01 01 00 00 00 08 3D CC       //Query all relays
Receive: 01 01 01 00 51 88    //all relays off
Send: 01 01 00 02 00 01 5C CA       //Query relays 2
Receive: 01 01 01 01 90 48    //Relay 1 on
Send: 01 01 00 01 00 03 2D CB       //Query relays 1, 2, 3 status
Receive: 01 01 01 05 91 8B               //Relays 1 and 3 are on, relay 2 is off

All relays on: 01 0F 00 00 00 08 01 FF BE D5
All relays off: 01 0F 00 00 00 08 01 00 FE 95
0-1 on; 3-7 off: 01 0F 00 00 00 08 01 03 BE 94
Relays 1, 2, and 3 on: 01 0F 00 01 00 03 01 07 F3 55

Relay 0 flash on: 01 05 02 00 00 07 8D B0  //700MS = 7*100MS = 700MS
Relay 1 flash on: 01 05 02 01 00 08 9C 74  //800MS
Relay 0 flash off: 01 05 04 00 00 05 0C F9  //500MS
Relay 1 flash off: 01 05 04 01 00 06 1D 38  //600MS

Send: 01 02 00 00 00 08 79 CC    //Query all input channels
Receive: 01 01 01 00 51 88    //Inputs are all untriggered
Send: 01 02 00 00 00 08 79 CC    //Query all input channels
Receive: 01 02 01 41 61 B8    //Channels 1 and 7 input is triggered, and the rest of channels are not triggered
Send: 01 02 00 01 00 03 69 CB       //Query input channels 2, 3, and 4
Receive: 01 02 01 03 E1 89    //Channels 2 and 3 input is triggered, and channel 4 is not triggered

Read relay 1-8 control mode: 01 03 10 00 00 08 40 CC 
Read relay 1 control mode: 01 03 10 00 00 01 80 CA
Read relay 2 control mode: 01 03 10 01 00 01 D1 0A
Read relay 3-5 control mode: 01 03 10 02 00 03 A0 CB

Set relay 1 as Linkage mode: 01 06 10 00 00 01 4C CA
Set relay 2 as toggle mode: 01 06 10 01 00 02 5D 0B

Set channel 1-8 relay as Normal mode: 01 10 10 00 00 08 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0B 5C
Set channel 1-8 relay as Linkage mode: 01 10 10 00 00 08 10 00 01 00 01 00 01 00 01 00 01 00 01 00 01 00 01 7C B1
Set channel 3-5 relay as Toggle mode: 01 10 10 02 00 03 06 00 02 00 02 00 02 4A 4B

Send: 01 03 80 00 00 01 AD CA
Receive: 01 03 02 00 C8 B9 D2       //0x00C8 = 200 =V2.00