AS-Interface FK-VA Coupling Module, IP67
The Siemens 3RK1901-1HA00 is an AS-Interface FK coupling module designed for field-mounting digital I/O modules in IP67 environments. It uses an insulation piercing method to connect two yellow AS-Interface flat cables, with the connecting baskets electrically paralleled for T and cross feeders — meaning you can daisy-chain power and data through a single module without separate junction boxes. Rated IP67, the module handles washdown and wet-area deployment directly on machine frames or conveyors. The housing uses stainless steel threaded bushings and Viton gaskets; the scope of supply includes four shaped seals and three end seals, all Viton, so the assembly seals against coolant and process fluids without additional potting. Operating voltage follows the AS-Interface specification at 26.5 to 31.6 V. Contact load rating is 2 A — sized for powering the downstream I/O modules, not for switching loads directly. Mounts to wall or standard rail (DIN rail), which keeps the install consistent with the rest of the panel or junction box.