Plug coupling system for disengageable electrical connecting of a programmable field device with a field bus or with a progamming device

A plug coupling system serving for the disengageable electrical connecting of a programmable field device with a field bus or with a programming device, the field device has a measuring sensor for registering at least one process parameter (x11) and a transmitter connected with the sensor at least during operation for producing measurements (x12) from the registered process parameter (x11), the transmitter is adapted to be electrically connected with the field bus by means of a bus connection cable having a plurality of conductor wires at least for sending produced measurements onto the field bus and the transmitter is adapted to be electrically connected with the programming device by means of a device connection cable at least for receiving parametering data produced by the programming device, the coupling system comprising:

• a first coupling member connected with a transmitter-side end of the bus connection cable, said first coupling member has at least:
• a first contact element, which is galvanically, especially lastingly, connected with a first conductor wire of the bus connection cable, and a second contact element, which is galvanically, especially lastingly, connected with a second conductor wire of the bus connection cable;
• a second coupling member connected with a transmitter-side end of the device connection cable, said second coupling member has at least:
• a first contact element, which is galvanically, especially lastingly, connected with a first conductor wire of the device connection cable, and a second contact element, which is galvanically, especially lastingly, connected with a second conductor wire of the device connection cable;
• and
• a third coupling member, arranged on the transmitter side, having at least a first, a second and a third contact element, which contact elements are connected, especially lastingly, with the transmitter, wherein:
• said third coupling member is suited for selective, mechanically disengageable connection with said first coupling member or with said second coupling member such that at least two contact elements of said first coupling member or said second coupling member, as the case may be, always contacts a respective one of the at least three contact elements of said third coupling member, and the at least two conductor wires of the connection cable connected at the moment are each electrically connected with a respective contact element of said third coupling member;
• and
• the contact elements are so designed and so arranged in their associated coupling members, that the third contact element of said third coupling member, while not galvanically connectable with any of the conductor wires of the bus connection cable, is galvanically connectable with at least one of the conductor wires of the device connection cable.