Abstract: Operation of a microcomputer-based instrument is controlled by software including a control interface system, a command execution system, and a steady state system. The steady state system includes a group of subsystems operating as concurrent tasks, each carrying out various instrument operations. The control interface system includes a set of subsystems, each responsive to configuration control input signals from a separate control signal source, and each converting configuration control signals into "configuration commands". Each command identifies a particular procedure for configuring the operating state of one or more instrument hardware or software steady state subsystems of the instrument. Each command is stored in memory in one of several queues (one for each control interface subsystem) until the procedure it invokes is carried out.

Abstract: Menus displayed on a screen of an instrument permit an operator to adjust and monitor the operating state of the instrument. Various menus are added and removed from the display in response to changes in the operating state of the instrument so that those menus appropriate for the operating state of the instrument are automatically displayed while inappropriate menus are automatically removed from the display. Displayed menu items may be added, removed or modified in response to changes in the operating state of the instrument, as evidenced by changes in the configuration parameters, so that only those menu items which are appropriate to a given operating state are displayed.

Abstract: A computer-based digital oscilloscope includes a touchscreen mechanism for generating output signals indicating when an operator has touched the oscilloscope's screen and identifying a particular touch zone area that the operator has touched from among a plurality of touch zone areas of the screen. A computer which controls display of waveforms and other images on the screen, monitors the touchscreen output signals to determine whether the operator is touching a touch zone and to determine whether a portion of a particular image other than a waveform is displayed on the screen within boundaries of the touch zone.