SLC 500 | Allen-Bradley | 1746-ITB16 24V DC Fast Response 16-Channel Input Module

Product Description

The 1746-ITB16 (Part Number 1746-ITB16) is a high-performance, discrete input module engineered for the Allen-Bradley SLC 500 controller platform. Unlike standard DC input modules, this "Fast Response" version is specifically optimized for high-speed industrial applications where minimal signal latency is critical. It provides 16 high-density input points in a sink wiring configuration, allowing for rapid detection of sensor states and high-speed pulse inputs within the 24V DC nominal range.

The module is designed for reliability in demanding environments, featuring an extremely low signal delay—just 0.3 milliseconds for the "On" state transition. This speed makes the 1746-ITB16 an ideal choice for machinery involving high-speed counting, precision positioning, or rapid cycle times. It interfaces directly with the SLC 500 backplane, drawing a minimal 85 mA current, which preserves power budget for other chassis components.

Technical Specifications

• Series: SLC 500 I/O

• Model Number: 1746-ITB16

• Module Architecture: Fast-Response Discrete Input

• Number of Inputs: 16 Channels

• Wiring Configuration: Sinking (Sink)

• Nominal Input Voltage: 24V DC

• Operational Voltage Range: 10 to 30V DC

• Maximum Off-State Voltage: 5V DC

• Maximum Off-State Current: 1.5 mA

• Nominal Input Current: 8 mA @ 24V DC

• Signal Propagation Delay (Resistive): On = 0.3 ms / Off = 0.5 ms

• Backplane Current Draw: 85 mA @ 5V DC

• Thermal Dissipation: Approx. 0.2 Watts per point

• Physical Weight: 0.26 kg (0.56 lbs)

• Status Indicators: Integrated LED array for channel verification

Implementation and Maintenance

When installing the 1746-ITB16, engineers should prioritize its use for inputs that trigger high-priority tasks or fast-acting logic rungs. Because it is a sinking module, the field device must be of the sourcing (PNP) type. This module is compatible with all SLC 500 chassis and can be used alongside AC or relay modules to create a comprehensive I/O solution.

Engineering FAQ

How does the 1746-ITB16 differ from the standard 1746-IB16?The primary difference is the signal delay. While a standard 1746-IB16 typically has an 8ms delay to filter out contact bounce, the 1746-ITB16 features a 0.3ms delay. This enables the controller to respond to millisecond-level changes in sensor data.

Does this module require external power for its logic?No. The logic-side circuitry is powered through the SLC 500 backplane. However, 24V DC field power must be supplied to the sensors or switches connected to the input terminals to complete the circuit.