Overview
The Allen-Bradley 1771-NT1 is a high-resolution isolated analog input module designed for precision temperature measurement and industrial process control. This legacy PLC-5 module provides eight analog input channels with 16-bit conversion resolution, supporting thermocouple types B, E, J, K, T, R, and S, as well as resistance signals up to ±105 mV. The module delivers 1000V isolation between channels and operates from the backplane at 5 VDC (1A maximum), eliminating the need for external power supplies.
Key Features
- 8 high-resolution analog input channels with 16-bit conversion
- Supports thermocouple types B, E, J, K, T, R, S and millivolt inputs (±105 mV)
- 1000V channel isolation for noise immunity
- Cold junction compensation and self-calibration
- Block Transfer Read (BTR) and Block Transfer Write (BTW) instruction support
- Selectable alarms and input detection with self-diagnostics
Technical Specifications
- Input Channels: 8 analog inputs
- Input Types: Thermocouple (B, E, J, K, T, R, S) and millivolt (±105 mV)
- Resolution: 16-bit
- Channel Isolation: 1000V isolated
- Input Impedance: >10 MΩ
- Overvoltage Protection: 140V AC RMS continuous
- Power Supply: 5 VDC from backplane
- Backplane Current: 1A maximum
- Power Dissipation: 5W @ 5VDC
- Operating Temperature: 0–60°C (32–140°F)
- Storage Temperature: −40–85°C (−40–185°F)
- Relative Humidity: 5–95% without condensation
- Measurement Range: −270–1380°C across supported thermocouple types
Typical Applications
The 1771-NT1 excels in applications requiring high-accuracy temperature monitoring and control:
- Process furnace and oven temperature monitoring
- Cryogenic and ultra-high-temperature process control
- Industrial test and measurement systems
- Chemical reactor and distillation temperature supervision
- Food processing and sterilization validation
- Pharmaceutical manufacturing temperature logging
Compatibility & Replacements
Compatible With
- PLC-5 processors and 1771 I/O chassis
- Block Transfer (BTR/BTW) instruction-based communication
- Any 1771 chassis slot installation
Replaces / Drop-In Replacement For
The Allen-Bradley 1771-NT1 is a legacy analog module discontinued as of May 31, 2017. Direct equivalent replacements depend on your specific application requirements and PLC generation. For modern systems, Rockwell Automation recommends evaluating CompactLogix or ControlLogix platforms with contemporary analog input modules. Verify compatibility with your system integrator before ordering.
Works With
- PLC-5 programming environments and legacy Rockwell software
- Block Transfer Read (BTR) and Block Transfer Write (BTW) instructions
- 1771 remote chassis and distributed I/O configurations
