The Solenoid Interlocks ensure that sliding, hinged and removable guarding devices, such as grids, hoods or doors, cannot be opened until dangerous conditions (e.g. run-on movements) have been terminated. This takes place in co- rdination with the control system of a machine. Fail-safe standstill monitors or delay timers monitor run-on movements or time sequences. These Solenoid Interlocks are applicable where the opening of a guarding device represents a non-permissible intrusion in a production process.