2-Relay Ethernet Board

Compact Ethernet board with two 16A relays. Designed for safe remote control of two independent loads over an IP network. Ideal for opening gates, rebooting routers and small automation systems that need maximum reliability in minimum space.
2-Relay Ethernet Board - Image 1
2-Relay Ethernet Board - Image 3
2-Relay Ethernet Board - Image 4

SKU 7626-ETH-RLY02EAN 8219671020565Item type: Assembled,

Description

Devantech ETH002-B board with an Ethernet interface and two volt-free relay outputs rated up to 16 A. It can be controlled over a LAN (Local Area Network) or across the Internet (webpage). A free app is also available for Android and iPhone. It offers a 100 MB full duplex Ethernet connection, a configurable host name and the MQTT protocol with optional TLS encryption. The board is supplied ready assembled and tested. It has 2 relay outputs, N.O. and N.C. (24 Vdc or 250 Vac / 16 A), each with its own status LED. Power supply: 12 Vdc-500 mA, dimensions: 85 mm (length) x 66 mm (width) x 20 mm (height). Operating temperature: -40°C to +70°C.
First test

Network connection and HTTP access

IP addresses and DHCP server: the easiest way to use the ETH-RLY02 board is to connect it to a network with a DHCP server. In that case the ETH-RLY02 will have its IP address assigned automatically by the DHCP server.
If there is no DHCP server on the network, the fixed IP address 192.168.0.200 is used instead. To control the ETH-RLY02 use this fixed IP address, and your computer must be on the same subnet. Set your computer IP address to 192.168.0.x where x is between 1 and 255 but not 200, nor any other IP address already in use on the network. The subnet mask determines which IP addresses the PC can talk to; we set it to 255.255.255.0 so that the PC can talk to any module with an IP address of 192.168.0.x.

Access from the browser

Power up the board and plug in the ethernet port, then start your browser and type http://eth002 in the address bar (this only works on Windows); you should see the screen below.
Enter the following default login details (Username: admin – Password: password):
You should then see the web page below, from which you can switch the relays on and off, reach the technical documentation (in English) and the network settings.
Configuration
Clicking the configuration link lets you set the IP address and the subnet mask. The configuration page also lets you set a password that will then be required to change the state of the relay or of the digital outputs using TCP IP commands (TCP/IP password section). All the settings are saved in memory, so take care to remember your user name and password! The default password settings are shown in the picture below. There is also a latched outputs option, which automatically saves the state of the relays in the event of a power failure.
Test program and sample source code: you can study the source code to see how it works, or use it as a starting point for your own application.
Visual Studio Express is supplied free of charge by Microsoft: http://www.microsoft.com/exPress/download/

App for Android and iPhone
A free App for Android and iPhone is available that lets you control the relays remotely. You can download it from Google Play or iTunes. Search for “Devantech” and you will find the App.
Access from the Internet
The board can also be controlled over the internet through a broadband router. To reach the board from the internet you will need to open communication port 17494 (0x4456), which is set up to accept incoming TCP connections. Take care not to open any other port. Because there is such a wide variety of routers about, we cannot give the details for every one of them. If in doubt, ask your system administrator for help. Below we show how to open a port on a Netgear DG834 router.
After logging in to your router configuration page, the first thing to do is create a new service. Click the “Services” menu, then “Add Custom Service”. Enter a name for the service, select TCP and enter the start and end port address. Click “Apply”.

Now go to the “Firewall Rules” menu and click “Add” in the inbound services section. Select the ETH-RLY02 service and Always allow. The “Send to LAN Server” IP address is the IP address of the ETH-RLY02 board, 192.168.0.96 in the example above, but check what it is on your own network. Click “Apply” and that is all. The ETH-RLY02 can now be reached over the internet.
Before you close the Router setup page, go to the “Router Status” menu and make a note of the public ADSL port IP address. That is the IP address for access from the internet.
Dimensions
Technical specifications
  • Connections: screw terminals for N/O, N/C and common contacts
Documentation and useful links
  • Documentation ETH002-B
  • Java network scanner app, easily find your module even on another subnet – Devantech module finder
  • Examples:
    Java – command line application for controlling the module
    Perl – Simple example of setting an output active/inactive by tcp
    PHP script – Simple example of setting an output active/inactive by tcp
    Python V2 – command line application for controlling the module
    Python V3 – command line application for controlling the module
    Visual C# – source code for simple program, includes UDP scan to determine any boards connected to the local network
    Visual Basic – source code for simple program, includes UDP scan to determine any boards connected to the local network

Technical details

Relay outputs 2
Power supply - 12 Vdc mains adaptor
Configuration and test interface HTTP (webpage)
Control interface TCP/IP over Ethernet
Relay rated current up to 16A@24vdc or 250vac
Ethernet 100mb full duplex

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