The Allen-Bradley 1746-ITB16, also cataloged as the 1746-ITB16 Fast Response DC Sinking Input Module, operates as a dedicated hardware component for high-speed discrete signal acquisition within SLC 500 controller platforms.

Model Identification & Configuration

The 1746-ITB16 is a digital DC input module designed for SLC 500 chassis installation. The module provides 16 sinking input channels for 10 to 30 VDC field devices and is configured for applications requiring fast response to discrete input transitions.

Hardware Specifications

SLC 500 Industrial Control Signal Processing

The 1746-ITB16 uses the SLC 500 backplane communication structure to exchange input status data with the controller processor. Its fast response input circuitry is designed for discrete devices requiring shorter input transition detection time compared with standard digital input modules.

The module supports direct connection of sinking field devices where the input circuit detects current flow from the external device into the module input channel. Proper field wiring polarity and common terminal arrangement are required during installation.

Ordering Information

The supplied configuration normally includes:

• 1 x Allen-Bradley 1746-ITB16 Fast Response DC Sinking Input Module
• 1 x Factory installed terminal block interface
• 1 x Module housing assembly

Additional components required for operation may include:

• SLC 500 chassis assembly
• SLC 500 processor module
• Compatible programming software
• Field wiring accessories

Field Installation Guidelines

Chassis Mounting

• Install the module into an appropriate SLC 500 chassis slot.
• Confirm backplane connector alignment before applying insertion force.
• Remove power from the chassis before module replacement.

Field Wiring

• Verify that connected devices match the 10 to 30 VDC sinking input requirements.
• Maintain separation between input signal wiring and high voltage power conductors.
• Use shielded cable where electrical noise may affect fast switching signals.
• Connect field commons according to the module wiring specification.

System Integration

• Confirm processor compatibility with the selected SLC 500 configuration.
• Check input addressing after installation through the controller configuration software.
• Avoid disconnecting field wiring while the module is energized.

Frequently Asked Questions

• What type of input signals does the 1746-ITB16 accept?

The module accepts 10 to 30 VDC digital sinking input signals from field devices connected to SLC 500 control systems.

• How many input channels are available on this module?

The 1746-ITB16 provides 16 independent digital input channels for monitoring DC field devices.

• What is the nominal operating input voltage?

The nominal input voltage is 24 VDC, with an operating range from 10 to 30 VDC.

• Is the 1746-ITB16 designed for high-speed input detection?

Yes. The module is identified as a fast response input module for applications requiring rapid discrete signal recognition.

• What is the backplane current consumption?

The module requires 85 mA of backplane current load at 5 VDC according to the supplied technical data.

• Can this module connect directly to AC field devices?

No. The 1746-ITB16 is designed for DC sinking input signals and requires compatible DC field devices.

• Does the module support hot swapping during operation?

The SLC 500 system does not support removing or inserting modules under power. Always remove chassis power before replacement.

• What installation factors affect input signal quality?

Correct polarity, proper grounding, cable routing, and separation from electrical noise sources affect signal integrity.