Type 2 plug + connector systems, which are standardised in accordance with IEC 62196, can be used for single-phase and three-phase AC charging. The two signal contacts PP and CP are responsible for communication between the vehicle and charging point. For example, these contacts are used to signal whether the connector has been correctly inserted into the vehicle inlet and what current strength can be used for charging. A lock prevents the plug + connector from being disconnected during the charging process or before all necessary transactions (such as payment) have been completed. This ensures a high level of functional reliability.