Ethernet Relay Modules

Numato Lab’s EIGER WR8 : 8 Channel Web Relay Module is a versatile product for controlling electrical and electronic devices remotely from a PC over an Ethernet link and is designed for modern IoT, industrial, and smart automation applications.

It combines powerful data acquisition capabilities with seamless cloud connectivity and local control features. With integrated support for Wi-Fi 2.4GHz, MQTT/MQTTS (compatible with AWS, Azure, and other cloud platforms), and REST API, the Module empowers users to monitor, control, and automate processes remotely and securely. Ease of use and wider operating system compatibility are the primary goals behind this product’s design.

This simplicity allows the use of off-the-shelf Terminal Emulation programs such as HyperTerminal and TeraTerm for controlling the module with a simple set of human-readable commands through Telnet/Web page/Wi-Fi and/or REST API commands. For power users, this module can be controlled by writing programs in various programming languages. This highly versatile device allows users to create fully automated systems with minimal setup time. It is ideal for both professionals and hobbyists looking to integrate reliable automation and data acquisition into their systems.

Applications

• Industrial Automation: Monitor sensor inputs and control actuators, machines, or alarms based on configurable logic.
• Smart Home & Building Automation: Automate lighting, HVAC systems, and appliances using environmental data and remote control.
• IoT & Cloud-Based Monitoring: Stream real-time data to AWS, Azure, or private MQTT brokers for centralized dashboards and alerting.
• Environmental Monitoring: Use the onboard temperature and humidity sensor for weather stations, greenhouses, or storage rooms.
• Remote Control Systems: Operate devices from anywhere using the onboard web server or REST APIs.
• Data Logging and Analytics: Log inputs, outputs, and sensor data locally for historical analysis and compliance tracking.
• Smart Agriculture: Monitor field conditions and control irrigation or other systems based on environmental triggers.
• Test Fixtures
• DIY and Hobby

Board Features

• 8 Relay Outputs: Control external devices such as fans, alarms, or lighting with 8 independent relay channels, 10A maximum switching current.
• 8 Digital High Voltage Inputs supports Maximum Input Voltage of 24V.
• Relay LED indication: Each relay has individual LEDs for status indication.
• Password-protected Web console, Wi-Fi console, REST API and Telnet communication interface.
• 2-in-1 Sensor: Temperature and humidity sensing in a single device.
• Wi-Fi (2.4GHz): Provides stable wireless communication.
• DIN Rail Support: Supports standard DIN rail for easy installation.
• Cloud Integration: Supports MQTT, MQTTS for AWS, Azure, and more.
• Data Logging: Onboard Data Logging for secure, local storage of sensor and control data.
• Web Server & REST API: Built-in Web Server for configuration, monitoring, and remote control.
• Sensor and ADC Calibration: On-device calibration for accuracy.
• AP Mode for Device Configuration: Simplified configuration without a network.
• RGB Indicator: Easily shows device status with a color-coded RGB LED.

* All parameters considered nominal. Numato Systems Pvt Ltd reserve the right to modify products without notice.
* Datasheet – HF32FV-G Relay

The following section describes how to use this module.

Along with the module, you may need the items in the list below for easy and fast installation.

1. CAT 5e Ethernet Cable(Straight through cable)
2. 12V/24V 1A DC power supply
3. Medium-sized Philips screwdriver

Onboard USB port is available; the onboard USB Interface helps to communicate and configure this module seamlessly. This module is detected as a COM port, and the user can configure the module using any serial emulator program like Hyper Terminal, TeraTerm, etc. Use FTDI drivers for the USB COM port device.

Use a USB-A to USB-C/ USB-C to USB-C cable to connect to a PC. Please visit numato.com to buy cables and accessories for this product.

The onboard Ethernet port supports Ethernet 10/100 Mbps transmission speed that helps a computer to communicate and control this module easily.

You can connect the module to a Local Area Network(LAN) via a common straight-through Ethernet cable.

Eg: Connecting the module to a switch in a network.

The EIGER WR8 : 8-channel Web Relay Module offers effortless wireless connectivity with built-in 2.4GHz Wi-Fi, ensuring smooth and reliable network integration. With AP Mode, setup is quick and hassle-free, requiring no additional hardware. Once connected, the device efficiently transmits data to the cloud using MQTT/MQTTS, enabling real-time monitoring across multiple platforms. In STA Mode, once the device is configured, it will stay connected to the specified network and continuously publish data to the cloud, ensuring seamless data communication without the need for manual intervention. Secure access is provided through HTTP/HTTPS REST APIs, allowing for robust and real-time data communication. For added convenience, the module features a secure, built-in web interface that can be accessed directly from any browser for easy configuration and monitoring.

This module has eight Relays that can switch up to 10A current. All contacts on each relay are available externally on screw terminals for easy user access. The relays are rated for AC switching supply voltages. Please see the electrical parameter table for more details. Each relay has two contacts (IN and OUT). For the Relay, the contact will be established between the IN and OUT contacts when the relay is turned on and will be disconnected when the relay is turned off. The table below summarises possible relay contact positions.

This board can be operated with a single DC power supply. Use a 12V/24 1A DC power supply on the DC jack(J1) on the Board for both the logic circuit and relays.

Connecting the power supply incorrectly can cause damage to the module and/or other devices

The EIGER module has a multifunctional RGB LED Indicator. The device indicates the Power status, Configuration mode, Network status, MQTT connectivity, and Multipurpose switch state.

The EIGER WR8 : 8-channel Web Relay Module is equipped with a versatile multipurpose switch that enables a range of device management functions:

Important: Use the Factory reset feature only to recover the Username/Password/Hostname. A factory reset will erase all Network, MQTT, and other settings, restoring the board to its default configuration. After resetting, access the board using the default credentials listed in the table below.

Connection Diagram for AC Solid State Relay

The pictures above show the basic connection diagrams for AC loads that can be used in most situations. Please make sure to use a freewheeling diode or snubber circuit if the load is inductive. More details about using inductive loads are available elsewhere in this document. Use a Straight Through Ethernet cable for communication when connecting the board to a switch or router.

It is important to make sure that the wires used to connect loads are sufficiently rated to handle the expected load current. Exercise caution while working with high voltages. Short circuits can cause damage to the module. The following sections identify individual connections in detail.

The Multipurpose switch/the factory reset on the webpage is used to reset the settings on board to factory defaults. To execute a factory reset, please follow the steps below.

1. Press the RST (Multipurpose switch) for 15 seconds. (Or)
2. On the Device Settings page, under the Device management section, select the factory reset option, then click on the reboot button.
3. The RGB LED will blink for 5 seconds, and a solid RED colour will appear once the factory reset is done.

Please use this feature only for recovering the username/password. This action will reset the User name, Password, Device ID and also other settings as well. After reset, the board can be accessed using the default User name and Password as shown in the table below.

The factory default settings will be as below table.

Connect a DC power supply and power up the device as mentioned in the DC Power Supply section above. A red LED (PWR) will glow, which indicates active power. For configuration over USB, connect a USB-A to USB-C/USB-C to USB-C cable to the module, and also connect the module to a PC or a Switch/Router as mentioned in the Ethernet Interface section above. Run the Hyper Terminal program or any serial terminal program like PuTTY, TeraTerm, etc.

NB: By default, the module is configured with factory settings. To log in to USB configuration settings, users need to send a ‘reboot’ command from telnet or do a factory reset.

Select the module’s COM port and use the default settings, similar to the images below and connect.

Users will be prompted to enter the User name and Password. The default User name is ‘admin‘ and Password is ‘numatolab‘. You may change the User name and Password once logged in.

If the user name and password are correct, we will be able to see the login successfully message.

The EIGER WR8 : 8 Channel Web Relay Module offers a simple and hassle-free configuration process through its built-in Access Point (AP) mode. Follow these easy steps to get started:

Connect to the Access Point:

• Turn on the EIGER WR8 : 8 Channel Web Relay Module and wait for it to enter AP mode a Purple LED blinks indicating that the device is in Configuration mode.
• On your PC or mobile device, go to the Wi-Fi settings and connect to the EIGER WR8 : 8 Channel Web Relay Module‘s Wi-Fi network. The network name (SSID) will typically be  “Default Hostname” and the network password will the “Default Password”.
• Once the connection is established successfully, a Solid Purple LED Indication is visible.

Access the Configuration Page:

• Open any web browser and enter the default IP address of the EIGER WR8 : 8 Channel Web Relay Module (192.168.4.1) in the address bar.
• When prompted, enter the default password to log in and access the device’s configuration interface.

Configure the Device:

• Once logged in, you can easily configure Wi-Fi settings, MQTT cloud integrations, and more via the web interface.

Important Note: After you have saved all your settings on the device (such as device configuration, network, sensor, or MQTT configurations), the changes will only take effect after the device is rebooted. You can reboot the device either:

• From the Webpage: Use the Reboot option on the device management section to apply all settings.
• From the Multi-Functionality Switch: Click for 15 seconds, reboots the device with new configuration set.

Example commands and results after executing the commands.

Connect a DC power supply and power up the device as mentioned in the DC Power Supply section above. An RGB LED will glow Red for 2 seconds, which indicates active power. Connect the module to a Switch/Router as mentioned in the Ethernet Interface section above. Run Numato Lab Device Discoverer.jar, and click on Discover Devices. The window will display the IP address, Host Name, MAC Address, and Other information.

IP Address and MAC Address can be seen in the command prompt also, only after connecting the module through the web page. Open the command prompt and type the command ‘arp -a‘. This will display the available network interfaces and connected devices along with the MAC address and IP address of each device. Look for the IP address that corresponds to your device’s MAC address. The MAC address for each Relay Module is printed on a label on the board for your convenience. Use the IP address obtained to access the device.

The module can be monitored and controlled by using the interfaces below.

1. Through HTML/Web Page served from the device.
2. Through HTML/Web Page served from the WI-Fi interface.
3. Through a Serial terminal Emulator that supports TELNET (Eg: Hyper Terminal, TeraTerm, PUTTY…).
4. Through REST API commands.

The easiest method for controlling the module is through web page served from the device. To open the administration web page, type in the IP address in to the address bar of any web browser and press enter.

You will be prompted to enter your Username and Password. The default username is ‘admin,’ and the default password is unique for each device or the default “numatolab”. Once logged in, you may change the Username and Password.

Enter the default User name and Password, then click Sign In.

You will be presented with the device home page that shows the status of Relays and GPIOs

8 Relays on the board can be controlled over Ethernet. The Relay Index shows the corresponding relay on board. Relays on the board can be turned on/off by clicking the Toggle Relay button next to the corresponding relay index. The Status of the relays change automatically for easy identification.

This board has 8 general-purpose high-voltage inputs. The status of GPIOs is shown on the home page.

In the above image, we can see that Relay 0,5 and 6 are in ON position and rest of the relays are in OFF position.

The device Settings page displays the current firmware version, Device ID, Account Settings, and Basic Network Settings. A logged-in user can change and save the Device ID, User name, Password, and network settings.

In the above image, the firmware version is displayed as WA.00.01, default device ID 00000000, default User name is ‘admin’, and Password is ‘numatolab’. The user can change and save the Device ID, User name, and Password as explained in the command set or by changing the appropriate field on this page and clicking on the save button on the right side, and reboot the page from the Device Management section. The User name and Password can be reset to factory defaults via Factory Reset explained elsewhere in this document. The Basic Network Settings shows the Device’s MAC address, Host Name, DHCP Status, IP Address, Subnet Mask and Gateway. The default hostname and IP Address can also be changed according to the user’s wish. After saving changes, and rebooting the board will reboot with the new network settings.

The easiest method for controlling the module is through web page served from the device. To open the administration web page, type in the IP address in to the address bar of any web browser and press enter.

You will be prompted to enter Your username and Password. The default username is ‘admin,’ and the default password is unique for each device. Once logged in, you may change the username and Password.

Enter the default User name and Password then click Sign In.

You will be presented with the device home page where you can monitor the sensor data.

The Device Info section provides detailed information about your device. This section is read-only, which means you cannot modify the device information here, but you can refer to it when needed.

These details are displayed in a simple, easy-to-read format.

In the User Account section, you can manage your web login and Access Point credentials, including updating your Username and Password. This is important for keeping your account secure and ensuring only authorized users can access the device settings.

Important Note: Your password will only be updated if both the New Password and Confirm Password fields match exactly. If there is a discrepancy, a Warning message will be displayed, and you will need to correct it before proceeding.

Important Update Information: Once you update the User Account Password, both the web login password and the Access Point password will be updated simultaneously. This means that the new password will be used for both the web login to your device’s dashboard and for accessing the device through its wireless Access Point. Make sure to remember this new password for all future logins to your device.

The Firmware Update section allows you to keep your device up to date with the latest features and improvements.

Important: Do not upload any unauthorized images via OTA. Doing so may permanently damage the device.

The Backup Management section allows you to configure how your device logs sensor data locally for future analysis. You can choose from five different logging scenarios, depending on your needs. This enables you to control when and how sensor data is captured and stored on the device. In addition to selecting the logging scenario, you can also set the backup interval and choose the timezone for timestamping the logs when the device is connected to the network.

• Logging Scenarios:

• Backup Interval: Set how often the device should back up sensor data. You can choose the interval that best suits your needs (e.g., every 10 minutes, hourly, or daily). The interval determines how frequently the device logs and saves the data to the local storage.
• Timezone for Log Timestamp: Select the timezone that should be used to timestamp the logged sensor data when the device is connected to the network. This ensures that the data is recorded with accurate timestamps based on your local time zone, making it easier to analyze data in the context of your region.

Note:The device logs sensor data up to 500,000 data entries. Once the data reaches this limit, the device automatically overwrites the oldest data, starting from the first row, in a circular ring-buffer fashion.

In the Device Management section, you can perform essential actions to manage your device, including rebooting the device and restoring it to its factory settings.

Important Note:  Factory Reset is a permanent action. Once performed, all user-set data and logged sensor data will be erased. This action cannot be undone,  make sure to back up any important data before performing a factory reset.

The Network Settings section allows you to configure the network connectivity of your device. This includes the

• Wi-Fi Access Point Settings.
• Wi-Fi Station Settings
• HTTPS certificate settings.

In this section, you can view the SSID of the device’s Access Point. The SSID is a unique name assigned to each EIGER Wi-Fi Device, allowing you to identify and connect to the device’s access point.

Note: The Password for the Access Point is the same as the User Account password. That is once you update your User Account password, The Access Point password will also be updated automatically.

The WiFi Station Settings allow you to configure the device’s connection to an existing WiFi network. You can update the SSID, set the password, adjust the hostname, and configure the network settings according to your needs.

After configuration, the SenzConnect Module can be accessed via the DNS Hostname or the IP Address.

• Accessing via DNS Hostname:
  • The device will be accessible via its DNS hostname. By default, the device will be configured with a device specific unique hostname. The device can be accessed with the postfix “.local” example:  senzconnectstx.local.
• Accessing via IP address:

  • If the device was configured with a static IP address, you can access it directly by entering the static IP address into your browser.

  • If the device was set to use dynamic IP (DHCP), you can either check the IP address assigned to the device through your router’s DHCP table or use a “arp -a” on command tool and check the IP assigned to your device MAC.

Note:

• It is essential for the device to be connected to the WiFi network, to establish a connection to the MQTT broker, allowing it to publish data. Without an active network connection, the device will not be able to communicate with the MQTT broker, and as a result, data cannot be transmitted or received.
• Make sure the device has a stable connection to the network for proper data logging and remote communication. This connection is crucial for maintaining real-time data updates and ensuring that your device interacts with other systems in your setup.

The HTTPS Settings section allows you to configure secure communication for your device by enabling HTTPS. HTTPS is essential for encrypting the data transmitted between the device and the web dashboard, providing an extra layer of security for sensitive information.

Configuration Requirements:

• Server Certificate: This is the SSL/TLS certificate that verifies the identity of the server and establishes a secure, encrypted connection.
• Server Key: The server key is the private key that corresponds to the server certificate. It is required to complete the encryption/decryption process for secure communication. This key should be kept confidential, as it is critical for maintaining the security of your HTTPS connection.

How to Configure:

• Obtain Server Certificate and Key: You must have a valid SSL/TLS certificate and its corresponding private key. These can be generated from a certificate authority (CA) or created using a self-signed certificate.
• Upload the Server Certificate and Key: Upload the server certificate and server key files in the respective fields. These will enable encrypted communication via HTTPS.

Important Notes:

• Security: Always ensure that the server key is kept secure and never shared publicly. If compromised, the security of the HTTPS communication will be at risk.
• Certificate Expiration: SSL/TLS certificates have an expiration date. Ensure that your certificate is valid and renewed before it expires to avoid loss of secure communication capabilities.

The MQTT/MQTTS Settings section allows you to configure the communication between your device and the MQTT broker. You can choose to use either MQTT (unencrypted) or MQTTS (secure, encrypted MQTT).

The Sensor Settings page allows users to calibrate the connected sensors to ensure accurate readings. Calibration is a crucial process to adjust sensor readings for environmental or operational factors that may affect their accuracy. Proper calibration helps to enhance measurement precision and ensures the data you receive is reliable.

When to Calibrate:

• Initial Setup: Calibrate the sensors when the device is first set up to ensure the readings are accurate from the beginning.
• Periodic Calibration: Over time, sensors can experience drift, so regular calibration (e.g., every few months) is essential to maintain optimal performance.
• After Environmental Changes: If the device is moved to a new environment or exposed to significant changes in temperature, humidity, or air quality, recalibration may be required to adjust to the new conditions.

The simple set of ASCII based human readable command sets supported by this module makes controlling relays easy via TELNET protocol very easy. The following sections give examples of how to use the module with PuTTY and TeraTerm.

To use this module with PuTTY, please follow the steps below.

• Connect the module to the LAN.
• Open PuTTY and enter the IP address corresponding to the module, leaving the port number as 23.
• Click Open.
• If everything goes well, you should be presented with a screen as below.
• Type in the TELNET User name and Password when asked and press enter key.
• Commands listed in the table in  section “Sending Commands” can be entered here now. For example, here is the response for “ver” command.
• Using the relay module with TeraTerm is just as easy. Please follow the steps below.

TeraTerm is an open source software. A free copy can be downloaded from http://en.sourceforge.jp/projects/ttssh2/releases/

• Run TeraTerm and type in the IP address corresponding to the module in the “New connection” dialog and click OK.
• Then select the terminal setup from the setup button and make sure the settings are as shown below, and press OK.
• Type the User name and Password when asked.
• Press ENTER key and the command prompt should appear. Commands listed in the table in section “Sending Commands” can be entered here now. For example, here is the response for “ver” command.

This module supports REST API commands.

Refer to the ‘REST API Command Set‘ knowledge base to know more.

Below is the example image related to controlling these modules through REST API commands.

fig 1: Displays device ID

One of the most powerful features of this module is the simple easy to use command set it supports. This command set allows for a very simple interface to access the features of the module through TELNET protocol. The following sections give details of the command set and how to use the command set

This product supports a very simple command set that is designed to be less cryptic and easy to use manually (using terminal emulation programs that support TELNET) or through a program written in one of the many supported languages

List of currently supported commands.

The table below has more detailed information about available commands.

8 Channel Ethernet Solid State Relay Module do support Analog to Digital Conversion on some of the IO terminals. A list of GPIO’s that supports analog function in this product is listed elsewhere in this document. There is no special command is required to execute to switch between analog and digital mode. Executing “adc” command will set the GPIO to analog mode and executing “gpio” command will set the GPIO back to digital mode on the fly. Resolution of the ADC is 10 bits unless otherwise noted. The input voltage range of the ADC is 0 – VDD (this product uses 3.3V power supply, so the range will be 0 – 3.3V). The result will be returned as a number starting at zero and ending at 1023. Zero indicates zero volts at the ADC input and 1023 indicates VDD (3.3V for this product) at ADC input.

It is possible to read the position of a switch that is connected to a GPIO. A SPST or SPDT switch is recommended to use with GPIO’s. Push switches do maintain the contacts closed only for a very short time so using them is discouraged. The fundamental idea of using a switch with GPIO is to have the switch cause a voltage level change at the GPIO pin when pressed. Usually this is achieved by using an external pull-up resistor along with the switch. The pull up resistor is connected between the GPIO and VDD and the switch is connected between the GPIO and ground. When the switch is not pressed, the pull-up resistor will cause the GPIO to stay at VDD voltage level. When the switch is pressed, the GPIO is short circuited to ground and stays at zero voltage. This change in voltage and thus the position of the switch can be read using “gpio read” command. Please see the recommended connection diagram below

It is important to take additional care when using relays with inductive loads. An inductive load is pretty much anything that has a coil and works based on magnetic principles like Motors, Solenoids and transformers. Inductive loads produce back emf when the magnitude of the load current changes. The back emf can be in the order of tens or even hundreds of voltage (See this Wikipedia article http://en.wikipedia.org/wiki/Counter-electromotive_force). This effect is most severe when power is disconnected from inductive load because the rate of change of current is maximum at that point. Even though the back emf lives only for a very short time (a few milliseconds) it can cause sparks between the relay contacts and can deteriorate the contact quality over time and reduce the life span for the relays considerably.

So it is important to take countermeasures to suppress the back emf to acceptable levels to protect relay contacts. Usually this requires connecting electronic devices in parallel with the load such that they absorb the high voltage components generated by the load. For solenoids, connecting a diode (fast switching diode is recommended) in parallel to the load (in reverse direction to the load current) is very effective. A diode used for this purpose is usually called a freewheeling diode. Please see the diagram on the right for connection details.

A capacitor with proper rating is recommended for protecting the relay contacts when a motor is used as load. The capacitor should be rated enough to withstand the back emf that is generated by the motor. Please see the diagram below for connection details.

Please note that the relay modules are NOT shipped with back emf suppression devices pre-installed. The exact kind of suppression device and the parameters of the selected device can vary depending on the load itself. Some of the parameters that affects the suppression device selection are the inductance of the load, power supply voltage, load current, physical size/structure of the load etc.. It is obvious that it is impossible for us to predict these parameters and design required back emf suppression device and incorporate that on the board. So we believe this is a task best left to the module user. There is an excellent article on designing back emf suppression on Wikipedia at http://en.wikipedia.org/wiki/Flyback_diode

Q. What is the connector marked as ICSP on this module?
A. This connector is used to program the on-board microcontroller. This connector is primarily intended for factory use.

Q. I need a customized version of this product, can Numato do the customization for me?
A. Yes, we can definitely do customization but there may be minimum order requirements depending on the level of customization required. Please write to sales@numato.com for a quote.

Q. Where can I buy this product?
A. All Numato products can be ordered directly from our web store http://www.numato.com. We accept major credit cards and Paypal and ship to almost all countries with a few exceptions. We do have distributors in many countries where you can place your order. Please find the current list of distributors here.

With USB configuration