Railway-rated 8-channel AC input for extended-temperature S7-300 racks
The Siemens 6AG1321-1FF01-2AA0 is an 8-channel digital input module from the SIPLUS S7-300 family, designed for AC control voltages of 120/230 VAC at 47 to 63 Hz. It accepts a signal "1" from 79 to 264 VAC and a signal "0" from 0 to 40 VAC, with typical input currents of 6.5 mA at 120 V and 11 mA at 230 V. It carries EN 50155 certification for rolling-stock applications (sections 4, 5, 12; T1, Category 1, Class A/B per EN 50155:2007).
Lifecycle and sourcing — active, quoted to order
Approvals include UL (File E239877), CE, KC, EAC, and RCM (formerly C-TICK). The EN 50155 certification covers railway rolling-stock environments — temperature class T1, Category 1, Class A/B — making this module a documented spare for rail control cabinets.
The input filter is fixed (not parameterizable) with a 25 ms typical on-delay and off-delay. There are no diagnostic alarms, hardware interrupts, or group error LEDs — the only status indication is a green LED per channel. This is a straightforward, no-frills input module suited for simple AC sensing where fast response is not required.