The Allen‑Bradley 1771‑ICD is a digital input module from the PLC‑5 series designed to support high-density DC signal acquisition. It provides 16 sinking input channels compatible with 20–60 VDC field devices. Engineered for use in rugged industrial environments, the 1771‑ICD offers dependable input detection with solid-state circuitry and noise immunity. The module supports direct installation into a 1771 I/O chassis and uses the 1771‑WH wiring arm for streamlined connectivity. With reliable operation and flexible sourcing device compatibility, this module remains a strong choice for legacy PLC‑5 installations.