Complete system in which a safety device, a key store, a converter, a storage module, a field bus system, a parameterisation instrument and a superordinate controller are arranged, wherein the safety device functions as part of an electronic power drive system, which has an adjustable speed and is configured to be suitable for use in safety-related applications, and comprises: - at least one non-volatile storage element, which contains a parameter dataset for operating said safety device, - a key store, wherein the key store has at least one non-volatile storage element, wherein said storage element of the key store contains at least one data field that includes an item of checksum information of a safety device, wherein the safety device makes a physical interface available for exchanging data with a key store, wherein the key store is connected, in particular can be plug-connected, to the safety device through a housing of the safety device by way of an apparatus for receiving the key store, wherein the working range of the physical interface is limited in space, wherein the key store is configured such that it can be read out by the safety device via an electrically conductive connection consisting of just two lines, typically implemented in particular as a single-wire bus, wherein the key store is location-bound, that is can be fixedly assigned in space to a specific point within the complete system, wherein, using a means, in particular a connection chain, the key store can be fixedly connected to a location at which the safety device is also installed within the complete system, wherein the safety device can be swapped, in particular after a fault, wherein the key store of an old, in particular faulty, safety device can be connected to a new safety device, wherein the safety device has at least one calculation unit, which dynamically calculates an item of checksum information from the parameter dataset, wherein the safety device has at least one comparison unit, which compares the checksum information included in the key store with the dynamically calculated checksum information of the safety device, and makes the result available to the safety device as release information, wherein the operating state of the safety device is dependent on said release information of the comparison unit, wherein an item of release information that signals that the items of checksum information (4, 6) are identical enables the safety device to switch from a safe operating state to the normal operating state, and wherein an item of release information that signals that the items of checksum information (4, 6) are not identical enables the safety device to switch to a safe operating state. wherein the safety device functions as part of an electronic power drive system, which has an adjustable speed and is configured to be suitable for use in safety-related applications, and comprises: - at least one non-volatile storage element, which contains a parameter dataset for operating said safety device, - a key store, - at least one non-volatile storage element, which contains a parameter dataset for operating said safety device, - a key store, wherein the key store has at least one non-volatile storage element, wherein said storage element of the key store contains at least one data field that includes an item of checksum information of a safety device, wherein the safety device makes a physical interface available for exchanging data with a key store, wherein the key store is connected, in particular can be plug-connected, to the safety device through a housing of the safety device by way of an apparatus for receiving the key store, wherein the working range of the physical interface is limited in space, wherein the key store is configured such that it can be read out by the safety device via an electrically conductive connection consisting of just two lines, typically implemented in particular as a single-wire bus, wherein the key store is location-bound, that is can be fixedly assigned in space to a specific point within the complete system, wherein, using a means, in particular a connection chain, the key store can be fixedly connected to a location at which the safety device is also installed within the complete system, wherein the safety device can be swapped, in particular after a fault, wherein the key store of an old, in particular faulty, safety device can be connected to a new safety device, wherein the safety device has at least one calculation unit, which dynamically calculates an item of checksum information from the parameter dataset, wherein the safety device has at least one comparison unit, which compares the checksum information included in the key store with the dynamically calculated checksum information of the safety device, and makes the result available to the safety device as release information, wherein the operating state of the safety device is dependent on said release information of the comparison unit, wherein an item of release information that signals that the items of checksum information (4, 6) are identical enables the safety device to switch from a safe operating state to the normal operating state, and wherein an item of release information that signals that the items of checksum information (4, 6) are not identical enables the safety device to switch to a safe operating state.