Foxboro P0916AEOC I/A Series RTD Input Module with Over‑range Cut‑off Function

Technical Specifications Input Signal Type: 2‑wire, 3‑wire, 4‑wire RTD resistance signal Resistance Input Range: 0 Ω to 400 Ω Over‑range Hardware Cut‑off Threshold: 450 Ω Input Excitation Current: 0.2 mA typical value Channel Isolation Voltage: 500 V RMS Transient Surge Suppression: 1500 V Operating Power Supply: 24 VDC from system backplane bus Communication Protocol: Proprietary 2 Mbps HDLC fieldbus for I/A Series system Operating Temperature: ‑40 ℃ to +70 ℃ Storage Temperature: ‑50 ℃ to +85 ℃ Relative Humidity: 5%‑95%, non‑condensing Mechanical Dimension: Standard single‑slot plug‑in module for Foxboro I/A Series rack Certifications: CE, UL, ATEX, IEC 61508 functional safety compliance

Functional Features Supports multi‑channel RTD signal acquisition for 2‑wire, 3‑wire and 4‑wire connection modes. Built‑in hardware over‑range cut‑off protection for abnormal resistance input. High‑precision resistance‑to‑temperature conversion for Pt100, Pt1000, Ni‑type RTD sensors. Provides hardware filtering to suppress industrial electromagnetic interference. Channel‑to‑channel and field‑to‑backplane galvanic isolation.

Application Scenarios Process industry distributed control system (DCS).

Structural Characteristics Standard single‑slot plug‑in structure matching Foxboro I/A Series rack. Front panel with status indicator LED lamps for power, channel fault, over‑range alarm and fieldbus communication. Field signal terminals located at module front side for wiring maintenance.

Working Principle Field RTD resistance signals enter through terminal connectors. Hardware filter circuits eliminate high‑frequency interference signals. Built‑in over‑range cut‑off circuit monitors input resistance value in real‑time and triggers hardware protection once exceeding threshold. Isolation circuits complete electrical isolation between field circuit and internal logic circuit. Constant current excitation circuit drives external RTD sensors, and the sampling circuit converts resistance variation into digital temperature value.

Installation Requirements Install the module into designated slot of Foxboro I/A Series standard rack. Ensure rack ground connection strictly follows system grounding specification. Field signal wiring must use shielded twisted‑pair cables. Separate power cable and signal cable routing to avoid crosstalk.