Overview
The Allen-Bradley 1771-NR is a high-resolution isolated analog I/O module from the PLC-5 series designed for precision industrial measurement and control. The module has a 16-bit input resolution and a 14-bit output resolution. It is an 8-channel input module with isolated inputs. This module provides the high-accuracy analog signal conditioning required in applications ranging from process instrumentation to closed-loop control systems.
Key Features
- 16-bit input resolution and 14-bit output resolution
- All 8 inputs are isolated, reducing noise and ground loop interference
- Input overvoltage protection of 140 Volts AC RMS continuous
- Power dissipation of 6 Watts at 5 Volts; operating temperature range 0–60 degrees Celsius (32–140 degrees Fahrenheit)
- Maximum update time of 25 milliseconds for responsive feedback control
- High accuracy with Offset Drift ±25 mΩ/°C and Gain Drift ±50 ppm/°C
Technical Specifications
- Module Type: Analog input with isolated channels
- Input Resolution: 16-bit; Output Resolution: 14-bit
- Number of Channels: 8 inputs
- Backplane Current: 1.5 Amps
- Power Dissipation: 6 Watts at 5 Volts
- Operating Temperature: 0–60°C (32–140°F)
- Relative Humidity: 5–95% without condensation
- Update Time: 25 milliseconds maximum
- Input Overvoltage Protection: 140 Volts AC RMS continuous
- Mounting: Single slot in 1771 I/O chassis
Typical Applications
- Precision temperature and pressure measurement in process control
- RTD and thermocouple signal conditioning with isolated inputs
- Closed-loop proportional-integral-derivative (PID) control loops
- Data acquisition for industrial monitoring and diagnostics
- Integration with legacy PLC-5 systems requiring analog signal processing
- Equipment control requiring isolated analog feedback to reduce electrical noise
Compatibility & Replacements
Compatible With
- PLC-5 programmable logic controller series
- Allen-Bradley 1771 I/O chassis (1771-A1B through A4B and later)
- BDC or Natural Binary data formats for scaling and signal processing
- Industrial analog field devices: RTDs, thermocouples, pressure transducers, and 4–20 mA transmitters
Replaces / Drop-In Replacement For
The 1771-NR is a specialized high-resolution module. Verify compatibility with your system integrator before ordering to ensure it meets your specific I/O requirements and firmware support.
Works With
- PLC-5 ladder logic programming and RSLogix software
- DH+ and ControlNet communication networks (via compatible I/O chassis)
- Standard industrial analog signal ranges (voltage and current)
- 1771 series wiring arms and field terminal blocks
