flexible diagnostic system adaptable to systems of different size.

摘要

In a system for diagnosing information processor system units by diagnostic processor connected to said system units through an interface, in order to meet desire of increase and decrease of the system units, the interface comprises a plurality of port control units which have a circuit formation and are readily disconnected and connected thereto so that number of port controllers can be readily increased or decreased. The system units are classified into a plurality of primary group each having a predetermined number (m) of system units, the primary groups being classified into a plurality of secondary groups each having m primary groups, thus, groups of a low order being classified into groups of a higher order so that the group number of the maximum order becomes less than m. The port control units are corresponding to the order groups and are connected to one another in such a manner that lower order port control units are connected to higher order port control units. The port control units of the maximum order are connected to the diagnostic processor through a similar main port control unit and each of the primary control unit are connected to the system units. A specific one of the system unit numbers is supplied from the diagnostic processor to the primary port control units through port control units of the higher order control units so as to select a specific one of system units as a current diagnosed unit.