Arrangement having a safety-related system and method for the protected operation thereof by means of a remote query

A method for operating a configuration having a technical system and a controller controlling the technical system and can change a technical state of the technical system by means of control commands, which comprises the steps of:

• sending a remote query signal) to an interface device upstream of the controller by means of an external remote query device;
• checking, via the interface device, whether the remote query signal) contains a query command for querying system data stored as permissible in the interface device;
• passing through the query command contained in the remote query signal to the controller if the query command stored as permissible is contained in the external remote query signal, otherwise passing through of the query commend is omitted;
• and
• transmitting requested data to the external remote query device in a case of a permissible query command;
• wherein a data diode is connected in parallel to at least a last interface module of the interface device disposed in a cascaded configuration of interface modules of the interface device, seen from said external remote query device, that is to say, an interface module which is connected to the controller;
• wherein the data diode is polarized in such a way that the requested data can be sent in a direction of the external remote query device;
• and
• wherein in a presence of the query command, the requested data is transmitted via the data diode, and thus past the last interface module connected to the controller, to the external remote query device.