[en] A data acquisition and control system for the ETA-BETA experiment is presently under development at the C.G.I. of Padua. The system is based on a local minicomputer TI 960A linked via a telephone line to a host computer (IBM 370/158). The data collected during the experimentation are initially stored on a local disk unit and then transferred into large permanent files of the host computer. The experimentation requires a strict interaction between the operator and the computer. This interaction requires a sequence of operations which change according to the experiment requirements in an unpredictable manner. To avoid a continuous reprogramming of the operation sequence, to achieve a smooth and automated experimentation, a command interpreter which acts as an interface between the software modules performing different tasks and the operator has been implemented. The interpreter reacts to a command by activating a program which, under the operating system supervision, runs as an independent task or as a subroutine dynamically loaded in core. The operating power of the interpreter is enhanced by structure commands which perform looping and conditional branching as in a procedural programming language. The interpreter is open ended in the sense that new commands can be added during the operation and sequences of commands can be grouped in a procedure which can be executed by a single procedure call command. Nesting of structure commands and procedures is virtually unlimited