Using the UE9 for wireless data acquisition (App Note)

The UE9’s Ethernet interface makes it an excellent choice for doing wireless data acquisition.

The UE9 itself is not wireless, but it has a standard Ethernet interface which allows you to connect it to a wireless bridge or router allowing you to communicate with it as a wireless device. This is done using standard, inexpensive wireless equipment that can be found at any major electronics store. The easiest way to describe this, is to picture the UE9 connected to the network or PC with a cable, then remove part of the cable and replace it with a wireless link using common hardware that is easy to find and configure. There are several companies that produce wireless hardware that will work with the UE9. Anything designed for home or office networking would work perfect. Adding a wireless connection to a UE9 is no more difficult than doing it for your PC.

There are two kinds of wireless network setups, ad-hoc and infrastructure. Most wireless hardware supports both kinds of networks, but it’s best to check with the manufacturer to make sure.

In an ad-hoc network, all the nodes in the network (UE9, PC, PDA, etc.) all communicate directly to each other. In an infrastructure network, all the traffic passes through a single node, known as the access point.

There are two primary setups that will be addressed: Connecting the UE9 to an existing wireless network, and creating a wireless network to connect the UE9 to the PC.

Conecting the UE9 to an existing wireless network

If you are trying to add the UE9 to an existing wireless network, so the PCs on that network can communicate with it, then there is only one piece of additional hardware that you should need. A wireless bridge is a device with a wireless interface on one end, and a standard Ethernet interface on the other. There are several companies such as Linksys and D-Link that make easy to use, inexpensive bridges.

The first step in connecting the UE9 to the network, is to configure the bridge. Most bridges can be configured by connecting them to the PC via Ethernet cable, then changing the settings using a web browser or software that comes with the device. In order to get the bridge on the wireless network, you will need to make sure the bridge has the proper SSID, channel number, and security key (if applicable) of the wireless network. If you are unsure on these settings, you can always get them by connecting to the wireless router for the network. In this mode, the bridge should be configured to work in infrastructure mode, since the router will act as the control point for the network.

The next step is to configure the UE9. Connect to the UE9 from a PC using a usb or Ethernet cable. The UE9 needs to have a unique and valid IP address for the network, as well as a valid subnet and gateway. A typical network will have IP addresses in the 192.168.1.1 to 192.168.1.254 range. If your router has the IP address 192.168.1.1, then the default UE9 IP of 192.168.1.209 will work. The subnet in this case will also usually be 255.255.255.0 and the default gateway should have the IP address of the router (192.168.1.1) in this case. You can also set the option to have the UE9 automatically configured using DHCP if the router is acting as a DHCP server, and it will assign the above values automatically. If that is done, you can use a USB cable or the UDP locater feature of the LJControl Panel to find the IP address of the unit.

Once the UE9 and bridge are configured, you can connect the UE9 to the bridge via Ethernet cable. Sometimes it may take a minute or two until the network recognizes the UE9.

Conecting the UE9 directly to the PC using a wireless link

If there is no existing network, but you wish to communicate with the UE9 wirelessly, then you need to set up a network. If you have a wireless router handy, you can set it up in the infrastructure manner as described in the previous section.

However, you can also optionally use another bridge in place of the router (bridges are typically less expensive). In this case, all 4 devices should have separate IP addresses. 192.168.1.1–192.168.1.4 would work fine. Each bridge should be configured by connecting it to the PC, then using the bridges configuration software or website to change the settings. The bridges should both be set to work in ad-hoc mode (since there is no router) and given separate IP addresses. You must also assign them the same SSID and encryption key (if you are using encryption). Then, the UE9 should be configured in the manner above, and then connected to one of the bridges.

Minimal setup: UE9, WiFi router, and a laptop

Given the prevalence of laptops and other devices with built-in WiFi, it’s useful to consider a minimal, special case: Run an Ethernet cable to a WiFi router and connect to it from any laptop associated with the router. The prices of WiFi routers have fallen to the point where its feasible to consider buying a router just for this purpose. Note that there is only one blue box in this diagram:

In this way, the WiFi router and UE9 as a pair form a semi-portable wireless data acquisition network that client PCs can connect to.

WiFi Bridges and Routers

Part of the success of WiFi is due to the sheer number of choices of compatible devices. Any specific models listed here will surely become dated, but here is a list of devices worth mentioning in March 2010.

WiFi Bridges

We have found the ASUS WL330GE easy to use and reliable. The important thing when shopping for a bridge is to ensure that it supports the encryption method of your router. For our network, that meant we needed a bridge that supported WPA2. Our old Linksys WET11 bridge supported WEP only.

WiFi Routers

It’s easier to choose a WiFi router. You or your company probably already have one. If not, our network has had a few revisions of the Linksys WRT54G that have all worked well. For a high-power application, consider the EnGenius EOC-2610.

General Tips

There are several vendors of wireless bridges and access points, and a few different network types (i.e., 802.11a, 802.11b, and 802.11g). Most newer bridges and access points will work with the different network types (a, b, and g) but it’s best to check just to be sure.

If you are connecting the UE9 to an existing network, then it’s best to stay with the brand that the rest of the bridges and access points use, as that usually makes the configuration process easier. If you are setting up a new network, then it’s best to buy two bridges of the same make and manufacturer. Sometimes bridges and access points have special ways of configuring and naming things, or optional features that may or may not work with other brands.

To configure the UE9, start with a cabled connection to your network or PC, and assign it settings that make it work with that setup. Once that is configured and software can communicate with it, replace the cable with the wireless link.

Some offices and households can have interference on the 2.4 Ghz band that the 802.11b and 802.11g networks use. We have found that switching to a 802.11a network at the 5 Ghz band can give a stronger connection where interference may be present.

If you have simple questions about using the UE9 for wireless connections, we can answer them here. However, if you have specific questions on configuring your hardware or what settings you should use, you may find more help from the users guides and from your network administrator.