Product Summary
The Allen-Bradley 1771-IH is a robust digital DC input module for PLC-5 systems. It offers 8 sinking inputs with a 24-50V DC operating range. This rack-mountable unit ensures reliable signal acquisition in demanding industrial environments. Its straightforward design simplifies installation and maintenance.
[Theme A: Product Procurement & Buyer Guide]
Selecting Your Input Module
Procurement managers must match the module to their system's voltage needs. The 1771-IH operates on a 24 to 50 Volt DC supply. It fits perfectly within the Bulletin 1771 rack architecture. This compatibility ensures seamless integration into existing control panels.
Voltage and Current Specifications
This module's voltage category spans from 10 to 60 Volts DC. Your system's sensor signals must fall within this range. The nominal input current is 8.4 mA at 24V DC. At 48V DC, it draws 20 mA. These values help your team estimate total system power draw accurately.
Key Electrical Thresholds
Engineers must verify the on-state and off-state voltages. The maximum on-state voltage is 10V DC. The maximum off-state voltage is 4.5V DC. The maximum off-state current is 1 mA. These thresholds define clear logic levels for your input signals.
Backplane Power Consumption
The 1771-IH module draws a backplane current of 74 mA at 5V DC. This power consumption affects your PLC chassis power supply sizing. Proper planning prevents system overloads. This module also dissipates between 0.4 W and 8.1 W of power.
Wiring and Mounting Details
Installation uses a standard 1771-WA wiring arm. This design speeds up field wiring and replacement. The module mounts directly into a 1771 rack. This mechanical simplicity reduces installation time for your technicians.
[Theme D: Expert Technical Evaluation & Performance Review]
Signal Processing Delays
Signal propagation delays are critical for time-sensitive applications. The 1771-IH has a turn-on delay of 15 ms (+/- 7 ms). The turn-off delay is 20 ms (+/- 9 ms). These values ensure predictable response times for your control logic.
Isolation and Impedance
This module provides strong electrical isolation. Its input-to-backplane isolation voltage is 1500V AC RMS. This protection guards against ground loops and transient surges. The on-state input impedance ranges from 2.5 to 3 kΩ. The off-state impedance measures 5 to 6 kΩ.
Environmental Operating Range
The 1771-IH operates reliably in harsh settings. Its ambient temperature range is 0 to 60 degrees Celsius. This tolerance suits most factory floor conditions. The module's thermal dissipation reaches a maximum of 27.7 BTU/hr.
Status Indicators
Eight red status indicators are present on the module face. Each LED corresponds to one of the eight input channels. These lights give immediate visual feedback on input states. This feature speeds up initial system commissioning and field troubleshooting.
Logistics & Standard Packaging Details
