1771-IVN Allen Bradley 32-Point Low-True DC Input

Product Overview

The Allen-Bradley 1771-IVN is a 32-point low-true digital input module for the PLC-5 platform. It accepts 10-30 V DC sinking inputs in four groups of eight, designed for applications requiring low-true logic compatibility with sourcing field devices.

Technical Specs

• Input points: 32 (4 groups of 8)
• Voltage category: 10-30 V DC
• Logic: Low true (sinking)
• Backplane current: 700 mA @ 5 V DC
• Wiring arm: 1771-WN
• Addressing: Supports 1/2, 1, and 2-slot addressing

Key Features

• High-density 32-point design reduces rack space per input point
• Group isolation limits fault propagation between input groups
• Low-true logic suits sinking-input applications
• Direct backplane interface with the PLC-5 processor

FAQ

• What does low-true mean? The inputs register as ON when the corresponding input image bit is cleared (0), opposite of standard high-true modules.
• Which wiring arm is required? The 1771-WN 40-terminal wiring arm.
• Is it compatible with PLC-2 or PLC-3? The 1771-IVN is designed for PLC-5 systems using 1771 I/O chassis.

Installation Guide

1. Power down the 1771 I/O chassis.
2. Insert the module into any slot except the leftmost (adapter/processor) slot.
3. Attach the 1771-WN wiring arm and connect field wiring.
4. Set the chassis addressing mode (1/2, 1, or 2-slot) per system design.
5. Apply power and verify input status LEDs respond to field device states.

Selection Tips

• Select the 1771-IVN for low-true sinking inputs; use 1771-IBN for high-true applications.
• Confirm field device voltage stays within 10-30 V DC.
• Verify chassis power budget: 700 mA @ 5 V DC per module.