Equipment and a plug-in unit of the equipment

Equipment comprising:

• one or more plug-in units involving a first plug-in unit,
• a body device for receiving the one or more plug-in units, and
• electrical connectors in the one or more plug-in units and in the body device, the electrical connectors being suitable for providing galvanic contacts between each of the one or more plug-in units and the body device,
• wherein at least the first plug-in unit comprises at least one mechanical structure enabling the first plug-in unit to be locked in its operating position with respect to the body device with a fastening element, and the first plug-in unit further comprises a sensor circuit having first electrical properties when the fastening element is in a position locking the first plug-in unit in the operating position and otherwise electrical properties differing from the first electrical properties, and the equipment comprises a first monitoring circuit for generating a first signal indicative of a difference between the prevailing electrical properties of the sensor circuit and the first electrical properties.