A circuit arrangement for telecommunication installations wherein different types of messages, the type being a function of the origin of the message, are transmitted between a central control means and individual apparatuses, comprising:
- transmission line means connecting said central control and said individual apparatuses for information exchange,
- said individual apparatuses being formed into groups of like type,
- means associated with each said group of individual apparatuses for transmitting over said line means address information particularized to that group, indicating the identity of the group, and thereby the type of apparatus in that group,
- said individual apparatuses otherwise being operative to transmit information signals of like characteristics,
- a plurality of connection control means interposed in said transmission line means between said individual apparatuses and said central control means, each of said connection control means being connected to a plurality of individual apparatuses, each said connection control means including means for selecting one of a plurality of information signals received from the respective individual apparatuses connected thereto and for effecting a connection of the individual apparatus causing the transmission of the selected information signal to said transmission line means, said connection control means further including means for determining the address of an individual apparatus upon the production of an information signal from said individual apparatus and for transmitting said address jointly with the information to be transmitted to said central control means and
- means in said central control means for evaluating said information signals and said address information and for interpreting said evaluated information signals in accordance with the result of the evaluation of said address information.