Product Overview
The Allen-Bradley 1746-INT4 is a SLC 500 Isolated Thermocouple/mV Analog Input Module designed for precise temperature and millivolt signal acquisition. As a Four (4) channel input module, it accepts a wide range of thermocouple types—C, D, J, K, T, E, R, S, B, and N—as well as –100…100 mV dc signals. This module converts analog sensor data into digital values that any SLC 500 processor can retrieve, making it an essential component for industrial temperature monitoring and control systems.
With its rugged construction and field-proven reliability, the 1746-INT4 ensures accurate and stable readings even in demanding environments. Whether you are upgrading an existing line or building a new control panel, this module delivers the performance and flexibility your application requires.
Technical Specifications
The table below lists the key specifications for the Allen-Bradley 1746-INT4. All values are sourced directly from the manufacturer's data.
| Specification |
Value |
| Manufacturer |
Rockwell Automation |
| Series |
SLC 500 |
| Module Type |
Isolated Thermocouple/mV Analog Input Module |
| Backplane Current (5 Volts) |
110 milliamps |
| Backplane Current (24 Volts) |
85 milliamps |
| Inputs |
Four (4); Isolated |
| Thermocouple Sensors |
Type C, D, J, K, T, E, R, S, B, and N |
| Bandwidth |
8 Hertz |
| mV Signal Inputs |
–50…50 mV dc, –100…100 mV dc |
| Thermocouple Linearization |
IPTS–68 standard, NBS MN–125, NBS MN–161 |
| Cold Junction Compensation Accuracy |
±1.5 °C (34.7 °F), 0 … 70 °C (32…158 °F) |
| Open-Circuit Detection |
Upscale, downscale, or zero |
| Step Response |
100 milliseconds in, 2.5 milliseconds out |
| Open Circuit Detection Time |
5 s, typical |
| Update Time |
500 milliseconds |
| Resolution |
16 Bits |
Industry Applications
The 1746-INT4 excels in applications that require accurate temperature measurement and mV-level signal processing. Typical use cases include:
- Process control in chemical and petrochemical plants where precise thermocouple readings are critical.
- Monitoring of furnace or kiln temperatures in metal processing and ceramics manufacturing.
- Data acquisition systems that interface with transducers producing millivolt outputs, such as strain gauges or pressure sensors.
Thanks to its open-circuit detection and cold junction compensation, the module ensures reliable operation even when sensor wiring develops faults. The ability to select upscale, downscale, or zero output on fault conditions simplifies integration with HMI or SCADA systems, providing immediate visibility into signal integrity.
Installation & Setup Guidance
When installing the 1746-INT4, follow these practical steps to ensure optimal performance:
- Mount the module in any available slot of a SLC 500 chassis, ensuring proper backplane connection.
- Wire thermocouple sensors to the module's terminals, respecting polarity and using appropriate thermocouple extension wire.
- Configure the module's jumpers or software settings to match the thermocouple type and temperature scale (°C or °F) as required by your application.
- For mV inputs, verify the signal range (–50…50 mV or –100…100 mV) and set the module accordingly.
- After installation, perform a field calibration and schedule annual recalibration to maintain accuracy, as the manufacturer recommends.
Always refer to the SLC 500 installation manual for detailed wiring diagrams and safety precautions.
Maintenance & Reliability
The 1746-INT4 is built for long service life, but routine maintenance is essential to sustain accuracy and reliability. Inspect the module and its wiring connections periodically for signs of corrosion, loose terminals, or damaged cables. Because the module requires field calibration, plan to recalibrate at least once per year. Environmental conditions also affect performance—operate the module within its specified temperature and humidity ranges (0–60 °C, 5–95% non-condensing) to avoid drift or premature failure. By following these simple practices, you can extend the module's lifespan and minimize unplanned downtime.
Compatibility & Integration
The 1746-INT4 is part of the Allen-Bradley SLC 500 family and integrates seamlessly with any SLC 500 processor. It communicates over the backplane, so no additional network interfaces are required. The module's digital output data can be read by ladder logic or other programming environments, making it easy to incorporate into existing control strategies. Whether you are expanding an existing SLC 500 system or replacing a legacy module, the 1746-INT4 offers drop-in compatibility.
Buying Guide
Before purchasing the 1746-INT4, verify that your system uses a SLC 500 platform and that you have an available slot in the chassis. Confirm the thermocouple types and mV ranges you need are supported—this module covers all common types. Also, check the backplane current consumption (110 mA @ 5VDC, 85 mA @ 24VDC) against your power supply capacity. For genuine Allen-Bradley parts and reliable service, PLC Source PRO is your trusted supplier. We stock a wide range of industrial automation components and can help you find the right part for your application.