Product Summary
The 1771-IM digital input module from Allen-Bradley delivers eight reliable inputs for AC and DC signals. It operates with 220 Volts AC/DC and handles voltages from 184 to 276 Volts. This module connects pushbuttons, limit switches, and float switches to your PLC-5 system.
Product Procurement & Buyer Guide for 1771-IM
Engineers and procurement managers require a robust input module for high-voltage industrial automation environments in modern plants. The 1771-IM directly meets these demanding specifications by offering a versatile dual AC and DC input capability. You can use it with 220-240V AC at 47-63 Hz or 240V DC for maximum flexibility. This unique dual-voltage feature simplifies inventory management and reduces the number of spare parts needed.
The module features eight inputs with a voltage category of 220 Volts AC/DC for consistent performance across applications. Its AC operating voltage range is 184-276 Volts and the DC range is identical for seamless operation. This wide operating window ensures stable input detection even during fluctuating line voltage conditions. The backplane current draw is only 75 mA, which minimizes the load on your power supply.
Key technical parameters help you select the correct module for your specific control system requirements. The off-state current is 1.0 mA maximum for both AC and DC inputs to prevent false triggering. Signal delays are critical for timing: AC on-delay is 20 ±6 ms and off-delay is 20 ±6 ms. DC on-delay is 10 ±4 ms and off-delay is 20 ±9 ms for accurate logic control.
The module uses a 1771-WA wiring arm for secure and reliable field wiring connections. It mounts directly into any standard 1771 I/O chassis for easy installation. This streamlined design reduces installation time and simplifies future maintenance tasks. For procurement, always specify the exact catalog number 1771-IM to ensure compatibility with your existing backplane.
Expert Technical Evaluation & Performance Review
This section provides an engineering critique of the 1771-IM based on published technical specifications from the manufacturer. The module supports both AC and DC input types without requiring any internal modification or configuration changes. This dual-mode capability is rare and highly valuable for mixed-signal industrial environments. The nominal input currents are 2.6 mA at 240V DC, 3 mA at 220V AC 50 Hz, and 3.5 mA at 220V AC 60 Hz.
These low input currents reduce heat generation and allow longer cable runs without signal degradation. The minimum on-state current is 2.9 mA, ensuring reliable detection of weak or distant input signals. Environmental tolerances are robust for typical industrial cabinet locations. The operating temperature range spans 32 to 140 °F (0 to 60 °C) and non-condensing relative humidity from 5 to 95%.
Power dissipation varies from 0.4 W minimum to 2.4 W maximum, and thermal dissipation ranges from 3.2 to 10.9 BTU/hr. These figures confirm the module's suitability for enclosed control panels without excessive heat buildup. The off-state voltage threshold is 92-114V AC, providing excellent noise immunity against electrical interference. Engineers should note that DC signal delays are shorter for on transitions compared to off transitions. This asymmetry may require timing adjustments in high-speed discrete control applications.
Logistics & Standard Packaging Details
- One Allen-Bradley 1771-IM digital input module in static-safe packaging
- One 1771-WA wiring arm for field wiring connections
- Product documentation and quick-installation guide
- Anti-static bag and protective foam for safe transit
We offer express shipping via FedEx, UPS, and DHL for fast delivery to your facility. Contact our sales team for bulk order discounts and lead time information.
