Fix a few bugs, add a few necessary options. The application was tested against Keithley 195A + Keithley 2400 combination of instruments hooked up to an AR488 (simple cyclic data gathering).
TODO: polish command and selection system so that you won't have to invent "hacks" like creating an empty command to force instrument selection prior to controller-wide read. Consider adding more instrument-wide and controller-wide parameters.