ABB – AI581-S – Safety Analog Input Module, 4 × 4–20 mA Channels, SIL 2/3, 24VDC

The ABB AI‑S (P/N SAPB) is a high-integrity safety-rated analog input module in the AC‑S (S) PLC series. It offers four configurable current inputs (– mA or – mA, ‑bit resolution) and provides SIL  performance across all channels, with up to SIL  achievable on two channels under discrepancy monitoring. Designed for functional safety applications, it features PROFIsafe-enabled, fast conversion, configurable filtering, and robust diagnostics.

• Inputs:  analog channels, – mA or – mA selectable, ‑bit resolution,  Ω input resistance  

• Safety Integrity: SIL  across all four channels; two-channel SIL  capability with built-in discrepancy supervision

• Safety Communication: PROFIsafe over PROFINET, designed for AC‑S systems  

• Supply & Power:  V DC (.–. V), approx.  mA; reverse-polarity protected  

• Performance: . ms conversion cycle; – ms configurable input filter;  ms input time constant; max  Hz signal frequency  

• Diagnostics: Front-panel LEDs for power, errors, and per-channel status; test-function support via PROFIsafe  

• Mechanical: Compact IP housing, DIN-rail mountable, . ×  ×  mm; weight approx.  g  

• Environment: Operating – °C (XC versions extend range), non-condensing humidity, compatible with harsh environments per AC‑S‑XC