NCD Articles Home Copyright © 20011, National Control Devices LLC
By Ryan Sheldon
Contact Us

Converting Ethernet Devices to Wi-Fi

Why use an Ethernet to Wi-Fi Adapter?
The Ethernet devices developed by National Control Devices have been extremely popular with customers over the years and are projected to increase in popularity due to the expanding market of Network accessible devices. As most people know there are generally two types of devices on a network; Wi-Fi Devices and Ethernet Devices.

The Problem:
While our Ethernet devices have been very popular, there have been many hurdles in developing a rock solid Wi-Fi Solution for our customers, this is due mainly to the nature of embedded Wi-Fi. Wi-Fi devices require some type of configuration to ensure they are connected to the desired network. Secure networks also require a security key, further complicating the need for user-friendly method of configuring the device before attaching to a network. We researched many options to add Wi-Fi devices, but we persistently ran into brick walls in terms of cost, features, and electronic complexity.

The Solution:
The solution to this however was very simple, and was directed to us by a customer who was also looking for a Wi-Fi solution. That is when we were introduced to a Ethernet to Wi-Fi adapter that works flawlessly with our existing Ethernet Devices. These off the shelf adapters offer network configuration that could not be simpler.

Now you may be thinking to yourself that it is an overkill solution, wouldn't it be cheaper to use a embedded Wi-Fi module? The answer surprisingly is no. Our cost for the Digi embedded Wi-Fi modules we were previously using was $135.00, which exceeds the costs of a Wi-Fi adapter and Ethernet communications module by nearly $30. So a Wi-Fi adapter beats out cost completely.

When we researched Wi-Fi communication modules from RedPine, we were first greeted with excellent technical support, but when we told them we would only be purchasing about 100 pieces at a time, they had no interest in answering our technical questions (we actually did review all of the supporting documentation before presenting any questions to RedPine, I guess we forgot to mention that we would be selling several thousand units per year). Nonetheless, the most viable Wi-Fi communications module was also out of the equation when our design engineers discovered that our firmware would have to be completely re-written. Additionally, persistent boot-up problems plagued the RedPine Wi-Fi module, despite following the recommended reset circuit diagram. So the most viable Low-Cost Wi-Fi solution was also out of the equation.

As we explored the idea of Ethernet to Wi-Fi conversion, we were surprised to discover that the problems we were facing had already been addressed with the Netgear WNCE2001 Wi-Fi adapter. Using a highly compatible Wi-Fi adapter means we can focus our development on Ethernet solutions and add a Wi-Fi front end for customers who need a Wi-Fi solution without having to completely re-engineer the firmware we have been perfecting over the years.

The Netgear WNCE2001 Wi-Fi Adapter

We have tested a couple of different Wi-Fi to Ethernet solutions and the Netgear Universal Wireless Internet Adapter really is the best solution despite its slightly higher price. It is simply engineered for better compatibility. It offers configuration that could not be simpler, network security protocols, reasonable cost, and compatibility with every Ethernet device we tested it with including our -NET and -ME Ethernet Relay controllers.

The marketed purpose of the Netgear WNCE2001 is to add Wi-Fi compatibility with popular video game systems. However, we have found the Netgear WNCE2001 is perfectly suited for use with our devices offering 100% compatibility and easy setup.

The only error we were able to generate with this Netgear Wi-Fi adapter was when it was moved from one network to another. If you have to change networks or want to use the device in different networks for any reason we recommend resetting the unit. Simply hold the Reset button on the unit for 5 seconds, then release. Now you can reconfigure the device for your new network. Please see the video on this page for complete setup instructions of the Netgear WNCE2001.
Network Control the Easy Way
The embedded network modules we have chosen for our product line were manufactured by a company called Digi International ( On their web site, they have a very cool little program that you install on your computer called "RealPort".  RealPort searches your local area network for a compatible Digi embedded network module.  Once it finds the module's IP address, it maps that IP address to a COM port on your PC.  So what you end up with is a Virtual COM Port over your Ethernet or Wi-Fi connection.  So to make this perfectly clear, you only have to know how to write programs that talk to a serial port, and anyone, even first time programmers, can do that REALLY FAST! 
RealPort is probably one of the best Virtual COM port emulators I have seen.  It is a lot more robust than you might expect for a free program, and it is well supported (meaning they are still improving it).  To date, it has never lost communication with our controllers (in other words, it has never flaked out for no reason).  And installation could not be easier.  During installation, it will even ask you what COM port you want mapped to the network device.  You can also use the installation to remove older devices, or to remap existing devices to different COM ports.  RealPort is one of the greatest technologies I have seen, because it allows us non-influential programmers control some pretty influential devices...all while expending the least amount of brain power.
As Complicated as you want to Make It
First of all, I have to confess that I am not much of a programmer, my background is very strictly related to Embedded microprocessor programming and circuit layout.  Most of my customers who call me ask if its possible to control our network devices directly without using RealPort for virtual COM communications.  And they always seem to know more about networks than I do.  And their request is motivated by good reason, RealPort will not allow more than one computer to talk to a single device, so it becomes necessary to use a more direct approach to communications with our Ethernet and Wi-Fi devices.  And let me reiterate this point, what I am about to tell you comes from my customers who work with networking a lot more than I do, and from a programmer that I work closely with in the development of our products.
You can talk directly to our Ethernet and Wi-Fi controllers by sending commands to port 2101.  Before doing this, you will need to know the IP address of the device.  The IP address will automatically be assigned to your network using ADHOC.  The easiest way (for me) to find the IP address of the device is to start (but not finish) installing RealPort.  During the installation process, the IP address of the device(s) will be shown in a window that appears.  Once you know the IP address, you must login into the device to change the default baud rate from 9600 to 115.2K baud.  You do this by entering the IP address into the address bar of your favorite web browser.  You will then be prompted with a Login and Password.  The default Login word is "root", the default password is "dbps".  You will use the built-in web server and your favorite browser to look through the settings and store the default baud rate.  Once you have changed the default baud rate to 115.2K baud, you are ready to talk directly to the device without any special drivers, from anywhere on the network.  You will be tempted to make other configuration changes while you are logged in, I strongly urge you to keep all other settings at their defaults, at least for the time being until you have it working.  Making any other changes can cause you to loose communications with the controller, and we will have to instruct you on a procedure that will allow you to restore all default settings.  I cannot stress this point enough, please do not make any other changes while logged in except the default baud rate, even if you really know what you are doing.
Embedded Web Server?  Can I Control Relays over the Internet?
Yes, this device has an embedded web server.  This means you can talk to this device from anywhere on the network by entering the IP address into your URL of your favorite browser.  This does NOT however mean you can talk to this device over the internet.  If you have a network printer, or a network router, then you know you can login to these devices to make configuration changes.  Our devices work the same way, and they are no-more accessible over the internet as your printer would be or your network router.  But if you had some server software and a static IP address, that would all be different....and any device on your local area network could be accessed over the internet....and that includes your new internet controlled relay board.
Can the Embedded Web Server be Used to Activate Relay?
Not at this time.  The embedded web server is currently used exclusively for the purposes of configuring the interface and handling network protocols and security settings.  Though we are researching possibilities for integrating a web server that activates relays.
Advantages of Ethernet Communications Disadvantages of Ethernet Communications
Network infrastructure is likely in place already.  Though communication speed is not as fast as other direct wired communication methods, it's generally not a concern in most control applications.
Low Cost Interface
Multiple Users can Talk to a Single Device  
Reasonably Fast Communication Speed  
Virtual COM Support for Easy Programming  
A Single Network Can Talk to LOTS of Devices  
Advantages of Wi-Fi 802.11b Communications Disadvantages of Wi-Fi 802.11b Communications
Network infrastructure is likely in place already.  Of all wireless technologies we have seen, this is actually the slowest we have worked with.  Having said that, you can still activate many relays per second, but there is sometimes a network lag.  This is not really a disadvantage of the embedded Wi-Fi module as much as it is a disadvantage of the 802.11b standard, and the overhead required for Wi-Fi network communications.  Despite speed disadvantages, it really is perfect for relay control applications....who needs to turn on a light within 10ms anyway?
Can't beat the Plug in and Go Freedom or Wireless Technology .
Multiple Users can Talk to a Single Device  
Reasonably Fast Communication Speed  
Virtual COM Support for Easy Programming  
A Single Network Can Talk to LOTS of Devices