Allen Bradley 1771-IL | PLC-5 Isolated Analog Input Module | 8-Channel

Product Description

The Allen Bradley 1771-IL is an isolated analog input module designed for legacy PLC-5 systems. It provides eight fully isolated differential channels, supporting both voltage and current input ranges. With high accuracy, auto-calibration, and robust isolation, this module ensures precise signal acquisition in demanding industrial environments.

Technical Specifications

• Manufacturer Allen Bradley

• Product Line PLC-5 Series

• Module Type Analog Input Module

• Part Number 1771-IL

• Number of Inputs 8 isolated differential channels

• Input Voltage Ranges +1 to +5 V DC, 0 to +5 V DC, ±5 V DC, ±10 V DC

• Input Current Ranges +4 to +20 mA, 0 to +20 mA, ±20 mA

• Resolution 16-bit binary across full range

• Accuracy (Voltage) Typical 0.01%, Max 0.05% @ 25 °C

• Accuracy (Current) Typical 0.06%, Max 0.1% @ 25 °C

• Backplane Current 1.3 A

• Data Format Natural Binary or BCD

• Channel Update Time 500 ms for 8 channels

• Internal Scan Rate 50 ms

• Chassis Compatibility All 1771 I/O chassis

• Wiring Arm 1771-WG

• Mounting 1-slot rack mountable

• Isolation 1000 V between channels

• Functional Highlights Auto-calibration, jumper-selectable voltage/current mode, open-circuit detection, overvoltage protection, block transfer instructions (BTW/BTR), LED indicators for diagnostics

Application Scenarios

• Precision analog signal acquisition in legacy PLC-5 systems

• Industrial processes requiring isolated differential inputs

• Environments where high accuracy and robust isolation are critical

FAQ

Q: How many channels does the 1771-IL provide?  A: It supports 8 fully isolated differential input channels.

Q: What input ranges are supported?  A: Voltage ranges include ±10 V, ±5 V, 0–5 V, and +1–5 V. Current ranges include 0–20 mA, +4–20 mA, and ±20 mA.

Q: Is the module compatible with all PLC-5 chassis?  A: Yes, it can be installed in any 1771 I/O chassis.

Q: How often should calibration be performed?  A: Auto-calibration is integrated, but periodic verification is recommended for critical applications.

Comparable Models

• 1771-IL: 8-channel isolated analog input module (this model)

• 1771-IFE: Non-isolated analog input module for standard applications

• 1771-IR: Resistance input module for specialized sensor measurements