A circuit arrangement for a telecommunications system, comprising:
- a plurality of inquiry locations at which information may be present and may be solicited, each of said inquiry locations assigned an address;
- a cyclically operating interrogation device for selective connection to and driving said inquiry locations to solicit information and to modify the frequency of interrogation of the individual inquiry locations depending on the appearance of solicited information to be called in;
- and
- memory means including an interrogation memory comprising a sequence of memory locations with corresponding note bit locations for storing a plurality of selection events within a overall control cycle by storing individual addresses of said inquiry locations a plurality of times at a corresponding number of memory locations regularly distributed within the sequence of memory locations, and for scanning each location a different number of times an interrogation memory selection means for cyclically reading the stored addresses to cyclically access said inquiry locations for soliciting information and upon failure to receive information from an accessed inquiry location to read the same address from the next memory location storing the same address and store a note bit in the corresponding bit location, and means for suppressing reading of an address in response to the appearance of a note bit for that address and then erasing the note bit.