Allen‑Bradley 1771‑NIV Analog Input Module

The 1771-NIV is an 8-channel high-resolution isolated analog voltage input module for Rockwell Allen‑Bradley PLC‑5 control systems, belonging to the 1771 N‑Series precision analog family. It accepts ±10V voltage signals from field sensors, adopts 16-bit ADC conversion and full channel galvanic isolation, and transmits digital measurement data to PLC‑5 processors via block transfer instructions for high-precision process closed-loop control.

This discontinued legacy I/O module is a vital maintenance spare for old production lines and power plant control systems. It occupies a single slot in the 1771 universal I/O chassis, relies on backplane 5VDC power without external power supply, and supports matched terminal cables 1771‑NC6 / 1771‑NC17 and termination base 1771‑RTP4 for stable field wiring.

Main Specifications

• Brand: Allen‑Bradley (Rockwell Automation); Model: 1771‑NIV; Series: PLC‑5 1771 N‑Series High Precision Analog I/O
• Channel Layout: 8 fully isolated analog voltage input channels, standard input range ±10VDC
• Conversion Performance: 16-bit high-resolution ADC, low measurement drift, typical full-scale accuracy ±0.1%
• Isolation Rating: Independent channel-to-backplane isolation, anti-surge protection against industrial voltage spikes
• Backplane Power: 5VDC from 1771 chassis, backplane current draw 1.2A, single-slot installation
• Matching Accessories: 1771‑RTP4 termination base, 1771‑NC6 / 1771‑NC17 signal cable
• Operating Environment: -20℃ ~ +60℃ working temperature, 5%–95% RH non-condensing, IP20 cabinet grade
• Data Transmission: Block transfer communication with PLC‑5 CPU, supports channel fault status feedback
• Diagnostics: Built-in open-circuit and over-range detection, front panel LED status indicators
• Certifications: CE, UL industrial EMC certification, compliant with discrete manufacturing and process control standards

Core Functions

• Collect ±10V analog voltage signals from pressure, displacement, speed and temperature voltage output sensors on production sites.
• 16-bit high-precision conversion captures tiny signal fluctuations, meeting precision control requirements for fine-tuned process parameters.
• Channel-by-channel galvanic isolation eliminates ground loop interference caused by long-distance field wiring and multi-device grounding differences.
• Block transfer data reading transmits all channel measurement values and fault codes to PLC CPU in one scan cycle to optimize program execution efficiency.
• Integrated self-diagnosis logic automatically alarms open-circuit and overvoltage faults to avoid blind monitoring of critical process loops.
• Standard 1771 chassis modular design allows quick disassembly and replacement during equipment overhaul to shorten production downtime.

Application Scenarios

• Voltage analog input spare replacement for Allen‑Bradley PLC‑5 control racks in thermal power plant turbine auxiliary monitoring systems.
• High-precision signal acquisition spare parts for chemical factories, metallurgical rolling mills and automotive assembly automation lines.
• Maintenance backup inventory for pulp & paper processing equipment, water treatment plants and old packaging machinery control cabinets.
• Matching analog I/O accessory paired with PLC‑5 CPU, 1771 series I/O chassis and ±10V output industrial sensors.
• Retrofit replacement components for aging PLC‑5 automation systems featuring signal drift, channel short-circuit and isolation failure faults.

• Global aftermarket spare stock for maintenance teams managing legacy Rockwell PLC‑5 distributed control equipment worldwide.