Remote Data Logging using pc-based instruments - Alan Tong

Up until the late 1980s, remote data acquisition was traditionally achieved by leaving standalone data loggers to record events and returning once in a while to collect data and/or change settings. Further, the actual data acquisition required bespoke hardware and software solutions, and was prohibitively expensive for all but the high-end applications. Then, in the early 1990s, PC-based instrumentation appeared on the scene and data logging changed forever.

Since the early days of electronics, data acquisition techniques have enabled us to measure quantities, such as temperature, light levels, voltages and currents, and represent them in easy-to interpret formats, such as tables and graphs. We have also had the ability to store data for future reference/interpretation and act upon the data when limits are exceeded.

However, until about fifteen years ago, to implement data logging required expensive hardware, dedicated software, highly-skilled technicians and a reasonably large budget. Thankfully, the arrival of PC-based solutions in the 1990s stripped data logging of its complexity and cost. The hardware simply slots into - or more frequently connects to - a PC and user-friendly data logging software does the rest: often guiding the user through logger configuration and interrogation.

The simplification of configuring and interrogating the data logger are far from the only benefits PC-based solutions deliver though. Clearly, once data is captured by a PC, not only is its storage simple but so too is its transfer over a network. This last aspect is of particular appeal to those either developing a data logging application from scratch or adding remote data logging to an existing infrastructure.

For example, many factories and offices are already over-loaded with routed wires and cables, so, compared to installing new cables just for data acquisition purposes, the prospect of sending measurements down existing network cables is very appealing.

As it is most likely that the factory/office will already have PCs dispersed in and around the site, (plus some sites might be connected to each other via intranet or internet), why not exploit this existing connectivity?