Good tools make life much easier. In addition to the common-place tools like multimeters, oscilloscopes, and power supplies, I use a couple of specialized tools for characterization of my audio circuits. Specifically, the HP 8903A Audio Analyzer and HP 3562A Dynamic Signal Analyzer come in very handy. Both of these instruments may be controlled via the HPIB interface. Many of the name-brand, VISA-compatible HPIB controllers are ridiculously expensive. But, thankfully, there are less expensive alternatives. Personally, I find the GPIB-USB Controller by Prologix to provide incredible bang for the buck. The slightly more expensive GPIB-ETHERNET Controller is even more versatile. It can be tucked away in the pile of test equipment and be accessed anywhere on the network, even wirelessly, (provided it’s within the same network segment).
To get the screen shots of my HP 3562A, and other instruments that support plotting through GPIB, I use 7470.exe included in KE5FX’s GPIB Toolkit. This software turns your PC into a HPGL plotter. Very handy…
I use various scripts for controlling the instruments. This provides a couple of advantages. First off, setting up some of these instruments requires significant button-pushing. If a step is missed during the setup, the test may run but the results will not be comparable to previous results. Hence, the scripts provide a way to standardize the tests. Secondly, having the ability to launch a script and having it run autonomously provides significant time savings and minimizes notation errors.
I am currently in the process of converting my MATLAB-based scripts to Python. In addition, I am changing from the GPIB-USB to GPIB-ETHERNET controller. Python is platform-independent, i.e. the same Python script will run under Windows, OS X, and Linux. My scripts are available for download below. They are provided as-is with no support and are intended as a starting point for people who would like to use the Prologix controllers to communicate with test equipment.
Python Scripts (current): [no link yet]
MATLAB Scripts (no longer maintained): MATLAB Scripts (.zip archive).