System for controlling the communication between a main device and an auxiliary device, said main device comprising: - at least one communication line for the data passage; - at least one control unit in data communication with the communication line and configured for communicating by the communication line according to a prefixed communication protocol, said control unit being configured for receiving one or more query data packets according to the communication protocol and for replying, if queried, with a reply data packet according to the communication protocol; - a device for interrupting the communication configurable between an interruption condition for interrupting the communication between the auxiliary device and said at least one control unit and an enabling condition for enabling the communication between the auxiliary device and said at least one control unit; - at least one main driving unit configured for reading data on the communication line, said main driving unit being further programmed for configuring the communication interrupting device in the interruption condition and/or in the enabling condition; - connecting means for enabling a data communication with at least the auxiliary device; said auxiliary device comprising: - at least one driving unit configured for generating a query data packet according to the prefixed communication protocol, said data packet being adapted to be sent to the communication line of the main device for querying at least the control unit present in the main device; - connecting means for enabling a data communication with at least the main device, characterized by the fact the driving unit of the auxiliary device is configured for further generating, according to a prefixed communication protocol and at least once, a data packet replying to said query data packet, said reply data packet generated by the driving unit simulating a reply of a control unit to said query data packet and containing an enabling code, the main driving unit being configured for reading at least the reply data packets passing on the communication line and configured for switching the communication interrupting device to the enabling condition as a function of the enabling code. - at least one communication line for the data passage; - at least one control unit in data communication with the communication line and configured for communicating by the communication line according to a prefixed communication protocol, said control unit being configured for receiving one or more query data packets according to the communication protocol and for replying, if queried, with a reply data packet according to the communication protocol; - a device for interrupting the communication configurable between an interruption condition for interrupting the communication between the auxiliary device and said at least one control unit and an enabling condition for enabling the communication between the auxiliary device and said at least one control unit; - at least one main driving unit configured for reading data on the communication line, said main driving unit being further programmed for configuring the communication interrupting device in the interruption condition and/or in the enabling condition; - connecting means for enabling a data communication with at least the auxiliary device; said auxiliary device comprising: - at least one driving unit configured for generating a query data packet according to the prefixed communication protocol, said data packet being adapted to be sent to the communication line of the main device for querying at least the control unit present in the main device; - connecting means for enabling a data communication with at least the main device, characterized by the fact the driving unit of the auxiliary device is configured for further generating, according to a prefixed communication protocol and at least once, a data packet replying to said query data packet, said reply data packet generated by the driving unit simulating a reply of a control unit to said query data packet and containing an enabling code, the main driving unit being configured for reading at least the reply data packets passing on the communication line and configured for switching the communication interrupting device to the enabling condition as a function of the enabling code. - at least one driving unit configured for generating a query data packet according to the prefixed communication protocol, said data packet being adapted to be sent to the communication line of the main device for querying at least the control unit present in the main device; - connecting means for enabling a data communication with at least the main device,