Siemens 6DD1688-0AD0 Interface Sub Module PLC Information Card

Siemens 6DD1688-0AD0 is a SIMADYN D SS4 communication submodule for CS7, providing a dedicated RS-232 interface used by USS communications (DUST 1, 2, 3, 7) in legacy Siemens automation networks. It is designed to be mounted as the SS4 submodule on a SIMADYN D CS7 carrier, with a 26-pin sub-D socket at the X5 position and a CS7-SS4/SS5 interface on the 48-pin carrier connector that links to the CS7 bus. In practice, this module extends CS7 communication between the host controller and peripheral subsystems in drive control systems, turbine management, and distributed process automation environments, enabling serial data exchange with USS-compatible devices. As a member of the SIMADYN D family, the 6DD1688-0AD0 supports the CS7 protocol stack used in older Siemens installations, offering a compact, board-level interface option for integrating RS-232-based devices into CS7 networks.