Software based instrumentation

Since the late 1980s there has been considerable growth in the provision of softwarebased instrumentation. A software instrument can be considered to be a way of presenting the data of the instrument in an effective and understandable way on a PC-based operator screen, for example. The user is able to create the necessary front panel interfaces to suit their specific requirements. The front panel on the operator screen (of a PC for example) can have knobs, switches, graphs and strip charts. This allows the user to display the inputs from the instrumentation system and shows the outputs to control devices in the field.

The user can position, size, label and configure the instrument’s data type, dimension and range easily and effectively. This is a very flexible way of displaying instrumentation information as the faceplate can easily be modified for the application. The typical steps one goes through to generate a complete system are firstly to build the front panel of the instrument with the necessary information displayed. The second step is to construct in block diagram form the functional blocks that interpret the commands from the user to the instrument and possibly do some background analysis of information coming in. These are constructed from palette menus. The whole structure is then compiled to ensure that its execution speed is as high as possible. The other obvious reason why software based instrumentation is becoming so popular is the lower cost and easy access to hardware than alternative approaches.