# PI3381 Complete Specifications | Triconex Trident Series Model: PI3381 Brand: Triconex (Schneider Electric) Product Type: High-Speed Pulse / Frequency Input Module System Affiliation: Trident SIS Safety System Safety Level: SIL 3 / TMR Triple Modular Redundancy ## I. Core Specifications ### Channel Configuration 16 independent pulse input channels Supports single-ended / differential signal access ### Electrical Input Input Voltage Range: 12～125 VDC Compatible with active sensors, MPU magnetic speed probes and encoders Input Impedance: 5 kΩ Isolation Rating: Field-to-system isolation with 1500 VAC withstand voltage ### Frequency / Counting Performance Maximum Input Frequency: 100 kHz Supports frequency measurement, pulse accumulation and rotational speed calculation Enables A/B phase speed measurement for quadrature encoding ## II. Environmental & Mechanical Characteristics Operating Temperature: -40 ℃ ～ +70 ℃ Storage Temperature: -40 ℃ ～ +85 ℃ Relative Humidity: 5%～95% RH, non-condensing Supports hot swapping and on-line replacement Full-channel self-diagnosis: alarms for wire breakage, short circuit and abnormal signals ## III. Architectural Features Standard TMR triple modular design with 2oo3 two-out-of-three voting logic No tripping or counting loss under single-point failure Compatible with Trident main control architecture and matched with dedicated backplane terminal base ## IV. Typical Applications Rotational speed / overspeed protection for steam turbines, compressors and fans Pulse flow collection for vortex and turbine flow meters Position and speed monitoring of incremental encoders SIS and ESD interlock systems in chemical, power, oil and gas industries