Troubleshooting Resources for the NI WLS/ENET-9163

Hardware: Multifunction DAQ (MIO)>>Wireless DAQ>>WLS-9163

Problem:
This KnowledgeBase explains various techniques for troubleshooting your NI WLS/ENET-9163 and emphasizes the importance of understanding the wireless environment in which the NI WLS/ENET-9163 will reside.

Solution:
Ethernet Configuration
There may be a few settings that can cause problems during initial setup, on some networks. Problems can stem from various setups:

Having security software enabled
Internet connection sharing is disabled
Having a computer with multiple network cards(NICs) (KnowledgeBase 4UIG5NP9: Troubleshooting NI WLS/ENET-9163 Initial Setup Issues)
Directly connecting the 9163 to a computer with a static IP address (KnowledgeBase 4QNB43D2: WLS/ENET-9163 is Undiscoverable Over Ethernet with Static IP)
Having a proxy server enabled on the host computer (KnowledgeBase 4VQBPQU8: MAX Finds My WLS / ENET Device, But I Cannot Configure It)

Other Resources

Wireless Configuration
It is very important to have a good understanding of the RF environment in which you will be taking wireless measurements. NI wireless data acquisition devices operate in the unlicensed ISM frequency band, meaning you must share bandwidth with all other wireless devices attempting to transmit data. The IEEE 802.11 (Wi-Fi) spectrum is divided into 14 channels, 11 of which are available in the United States. This DevZone provides in-depth information regarding the NI WLS-9163 and IEEE 802.11, and should be read by anyone deploying a wireless application. Typically, Wi-Fi networks reside on channels 1, 6, and 11. It is important to identify an open channel to use for data acquisition. There are a few third party tools that can aid you as you analyze your RF environment:

inSSIDer - This tool reveals all 802.11 networks in the area, as well as the channel they reside on. Use the tool to help select a wireless channel that is not in use.
NetSumbler - This tool is similar to inSSIDer.

For example, a company with a wireless network deployed occupies channels 1, 6, and 11. The NI WLS-9163 will perform better if a private network is configured for Channels 3 or 9, since those channels reside furthest away from other IEEE 802.11 activity in the corporate network.

Error Handling
Proper error handling in wireless data acquisition applications is essential. Even in the best RF environments it is possible for a wireless signal to become weak or momentarily interrupted. Therefore, it is important that the user design their wireless data acquisition applications with this in mind. Below is an example of a how to modify a shipping NI-DAQmx example for use with an NI WLS-9163 device.

Customizing a C Series Example Program for Wireless

Common Errors and Their Meanings

Error -50405 occurred at DAQmx Read (Analog 1D Wfm NChan NSamp).vi Possible reason(s): No transfer is in progress because the transfer was aborted by the client. The operation could not be completed as specified.
Error -201250 occurred at DAQmx Start Task.vi Possible reason(s): Measurements: Connection to the network device has timed out. The network device did not respond properly for a period of time. If timeout persists, contact your system administrator.

These errors generally mean the device encountered wireless problems. In order to eliminate the errors, you can try the following:

Lowering the sampling rate
Changing the wireless channel
Properly handling the error and restarting the acquisition as outlined in the section above.

Report Date: 04/24/2009
Last Updated: 02/03/2010
Document ID: 4WNDIMU8

Your Feedback!

Poor | Excellent

Yes

Document Quality?

Answered Your Question?

Please Contact NI for all product and support inquiries.