Abstract: A plug-in connector has a plug member and a locking device for securing the plug member on a counterpart. The locking device has at least one locking element having a release position and a locking position, wherein in the release position the plug member is removable from the counterpart and wherein in the locking position the plug member and the counterpart are locked relative to one another. An actuating element acting on the locking device is provided for moving the at least one locking element from the release position into the locking position in a radial direction relative to a longitudinal axis of the plug member.

Abstract: A connecting plug for connecting an input/output unit to a machine control with a central bus, wherein the input/output unit is to be connected to a multi-strand electrical cable connected to a bus node, has a housing with a first plug connection for an incoming cable and a second plug connection for an outgoing cable. The incoming cable is looped through to the outgoing cable forming a looped-through cable. The housing has a connector for the input/output unit. An electronic device is arranged in the housing and connected to the connector. The connector is connected by the electronic device to the looped-through cable.