Product Overview
The Allen-Bradley 1756-IT6I is a ControlLogix analog input module engineered for precise temperature measurement. It provides six individually isolated thermocouple and millivolt input channels, making it a reliable choice for demanding industrial environments. This module supports a wide range of thermocouple types including B, E, J, K, R, S, T, N, C, D, and L (TXK/XK), delivering 16-bit resolution for accurate data acquisition.
Part of the ControlLogix series, the 1756-IT6I integrates seamlessly into both local and remote I/O racks. It is compatible with any ControlLogix processor and communication modules, ensuring flexible system design. Whether you are upgrading an existing line or building a new installation, this module offers the performance and isolation needed for critical temperature monitoring.
Technical Specifications
The following key parameters define the operational capabilities of the Allen-Bradley 1756-IT6I:
| Specification |
Value |
| Inputs |
6 isolated thermocouple, 1 CJC |
| Input Resolution |
16 bits; -12…78 mV: 1.4 µV/bit (typical); -12…30 mV: 0.7 µV/bit (high resolution) |
| Supported Sensors |
B, C, E, J, K, N, R, S, T |
| Backplane Current (24 V) |
125 mA |
| Backplane Current (5 V) |
250 mA |
| Power Dissipation (Max) |
4.3 W |
| Module Scan Time |
25 ms min floating point (mV), 50 ms min floating point (temperature), 10 ms min integer (mV) |
| Data Format |
Integer mode (left justified, 2s complement), IEEE 32-bit floating point |
| Removable Terminal Blocks |
1756-TBNH, 1756-TBSH |
These specifications ensure reliable performance in temperature-critical applications. The high-resolution range (-12…30 mV) delivers finer granularity for low-level signals, while the multiple data formats provide flexibility for different control architectures.
Key Features & Benefits
-
Six Isolated Inputs: Each thermocouple channel is individually isolated, reducing noise and ground loop issues.
-
Wide Sensor Compatibility: Supports types B, E, J, K, R, S, T, N, C, D, and L (TXK/XK) for diverse process requirements.
-
High Resolution: 16-bit resolution with 1.4 µV/bit (typical) in the standard range and 0.7 µV/bit in high-resolution mode ensures precise measurements.
-
Flexible Data Formats: Choose between integer or IEEE 32-bit floating point to match your control system.
-
Fast Scan Times: 10 ms minimum for integer millivolt signals supports rapid process control.
-
Robust Protection: Overvoltage protection up to 120 V AC/DC safeguards the module from electrical transients.
Installation & Setup
Installing the 1756-IT6I is straightforward. Mount the module into any ControlLogix chassis, either local or remote. Connect the removable terminal block (1756-TBNH or 1756-TBSH) for signal wiring. Ensure proper grounding and shielding for thermocouple leads to maintain signal integrity. Configure the module using your ControlLogix programming software, selecting the appropriate thermocouple type, input range, and data format for your application.
Maintenance & Reliability
The 1756-IT6I is designed for long-term service in industrial environments. Its isolated inputs reduce the risk of damage from ground potential differences. Regularly inspect the terminal block connections and wiring for signs of corrosion or loosening. The module's low power dissipation (4.3 W) helps minimize heat buildup in the chassis. With no moving parts and solid-state components, routine maintenance is minimal, contributing to reduced downtime and lower total cost of ownership.
Compatibility & Integration
As a ControlLogix module, the 1756-IT6I integrates with all ControlLogix processors and communication modules. It supports both local and remote I/O configurations, making it versatile for distributed control systems. The module's data formats (integer and floating point) are compatible with standard ControlLogix tag structures, simplifying programming and data handling.
Selection Guide
When selecting the 1756-IT6I, verify that your thermocouple types and measurement ranges match the module's specifications. Confirm the required removable terminal block (1756-TBNH or 1756-TBSH) is available for your wiring needs. Ensure your ControlLogix chassis has an available slot and sufficient backplane power (250 mA at 5 V, 125 mA at 24 V). For procurement, PLC Source PRO offers genuine Allen-Bradley 1756-IT6I modules with reliable availability and competitive pricing.