Circuit arrangement for key-controlled switching devices in communication exchanges, especially telephone exchanges

摘要

Operating functions, on the basis of which a switching device can be set as required, but which are to some extent mutually exclusive, are assigned individually to the function keys in an input keyboard. Input information is fed to an evaluation logic circuit which, when a combination of mutually exclusive functions is entered, converts this combination into an alternative combination of functions. An alternative combination is selected of the type which, in comparison with the originally entered combination, has the minimum number of function changes. The functions are displayed according to the alternative combination by means of a display device. IMAGE