Monday, May 31, 2010

LAN based data acquisition (DAQ), why not have wireless capabilities built-in?

One Agilent instrument that I have been working with a lot lately is the new 34972A DAQ switch unit. This instrument is based off of Agilent’s popular 34970A product but has LAN (LXI) and USB connectivity. A lot of 34972A end users like the idea of using the LAN connectivity and the built-in LXI web interface to check how a test is going or monitor some measurement back at the environmental chamber or some other distant location without leaving their desk. From these same users I often get the request “why not add wireless LAN capability to the 34972A?” I explain how wireless connectivity can be achieved by connecting the 34972A to a commercial wireless router. The response I typically get is it would be nice if it were built-in.
These requests made me think, should we add wireless capability to our LAN capable instruments especially the ones that are often not right next to their user? The answer I came up with is NO (at least for now). Now I have two main reasons for my conclusion and they both have the best interests of the end user in mind. The first drawback is instrument cost would increase and the cost increase would be much higher than the cost of a commercial wireless router. The main reason for the higher cost is simply because commercial wireless routers are massed produced and test equipment is not. For instruments like the 34972A, which is known for its wide range of functionality at a low price, the increased would be noticed. Another drawback is the long turnaround life time on test equipment. A lot of test equipment goes for over a decade before a replacement comes around. Wireless technology moves much faster with security, speed, and error recovery features constantly being updated. This means most test equipment life cycles would far out live the internal wireless technology. Yes firmware updates could help, but I think a hardware road block would eventually be reached.
For now my opinion is wireless LAN technology is better off outside the instrument in an easily updatable low cost mass production form. Of course as Moore’s law continues and more ‘neat’ uses of wireless technology surface my opinion may change in the near future.