Changing tables are required in installations with more than one access. Its function is to connect the telephone of the house with the plate from where the call is being made. This changer has been designed for 1-line door entry panels, (4 + n analog system). Maximum 5 accesses. 1 changing table is required for each doorman access. Only in case of 2 accesses 1 changer is needed. It selects the origin of the call, allowing communication only with the panel on which it has been called and the activation of the corresponding door opener.