Product Overview
The Allen-Bradley 1746-NT4 is a Thermocouple/mV Analog Input Module designed for the SLC 500 system. It converts thermocouple or millivolt signals into digital data for SLC 500 processors. This module eliminates the need for an external power supply by drawing 5 Volts DC and 24 Volts DC from the SLC 500 backplane. It features two cold-junction compensation sensors to maintain thermocouple accuracy without offset voltages.
Technical Specifications Breakdown
Key parameters for the 1746-NT4 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | Thermocouple/mV Analog Input Module |
| Number of Inputs | Four (4) |
| Compatible Thermocouple Sensors | J, K, T, E, S, R, B and N |
| Compatible Millivolt Signal | +/- 50 mV and +/- 100 mV |
| Resolution | 16 bits in, 14 bits out |
| Backplane Current (5 Volts) | 60 milliamps |
| Backplane Current (24 Volts) | 55 milliamps |
| Backplane Power Consumption | 0.8W maximum (0.3W @ 5V dc, 0.5W @ 24V dc) |
| Update Time | 26 milliseconds-1.2 seconds |
| Operating Temperature | 0 to 60 degrees Celsius |
| Storage Temperature | -40 to 85 degrees Celsius |
Industry Applications
Using thermocouple types J, K, T, E, S, R, B, and N, it provides accurate readings across a wide temperature range. The 16-bit resolution ensures precise data for critical loops, reducing waste and improving product quality.
Installation & Setup Guidance
Install the 1746-NT4 in any I/O chassis slot except Slot 0. Use shielded twisted thermocouple extension wire for thermocouple inputs; for mV inputs, Belden 8761 or equivalent wire is recommended. The module auto-calibrates at power-up and whenever a channel is enabled, simplifying configuration. Set open-circuit detection to Zero, Upscale, or Downscale based on your fail-safe requirements.
Maintenance & Reliability
The module includes 5 green LED indicators—one for module status and one per channel—for quick visual diagnostics. Operating temperature range is 0 to 60 degrees Celsius, with storage from -40 to 85 degrees Celsius. Periodically inspect wiring and connections for corrosion or damage to maintain signal integrity.
Compatibility & Integration
The 1746-NT4 is compatible with both fixed and modular SLC 500 styles. It uses block transfers in remote I/O configurations. The module communicates via the backplane, requiring no additional cables.
Selection Guide & Purchasing Advice
When selecting the 1746-NT4, verify your SLC 500 chassis compatibility and available backplane current (60 mA at 5V, 55 mA at 24V). This module is a reliable choice for upgrading existing thermocouple inputs. Order from AutoDCSTech for genuine Allen-Bradley parts. Please verify current lifecycle status and availability with AutoDCSTech before ordering.
Availability & Condition at AutoDCSTech
| Part Number | 1746-NT4 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
