The Allen-Bradley 1746-IH16, also cataloged as the 1746-IH16 Current Sinking DC Input Module, operates as a dedicated hardware component for receiving high-voltage DC field signals within SLC 500 controller platforms. The module provides 16 input channels with 90 to 146 V DC sink signal compatibility for discrete monitoring applications.

Model Identification

The 1746-IH16 is a 16-point digital input module designed for SLC 500 chassis installation. The catalog number identifies the module electrical configuration and input voltage class. Related ordering references include 1746-1H16, 1746-IHI6, and 1746-IH16/C.

Hardware Specifications

Backplane Bus Communication and I/O Density

The 1746-IH16 integrates with the SLC 500 backplane communication structure for controller-to-I/O data exchange. Its 16-channel configuration supports I/O density scaling within SLC chassis layouts while maintaining the defined backplane current load requirement.

The module operates as a discrete signal acquisition point between field devices and the processor unit. Correct slot addressing and chassis configuration are required for proper controller recognition and input data mapping.

Ordering Information

The delivered package contains:

• 1 x Allen-Bradley 1746-IH16 Current Sinking DC Input Module
• 1 x Factory identification label with catalog information
• 1 x Protective packaging suitable for industrial electronic components

Additional accessories may include:

• SLC 500 chassis system components
• Terminal blocks compatible with the selected installation configuration
• SLC programming and configuration equipment

Field Installation Guidelines

Module Mounting

• Install the module into a compatible SLC 500 chassis slot.
• Confirm chassis power is removed before module insertion or removal.
• Verify module keying and slot position before operation.

Electrical Wiring

• Connect field DC input signals according to the module terminal assignment.
• Separate high-voltage DC signal wiring from communication and low-level analog wiring.
• Use proper grounding methods for cabinet installation.
• Check field polarity before applying voltage to input channels.

System Configuration

• Configure the module type correctly within the SLC controller project.
• Verify input addressing after installation.
• Confirm processor communication status before placing equipment into service.

Frequently Asked Questions

• What type of input signals does the 1746-IH16 accept?

The module accepts discrete sinking DC input signals within the specified 90 to 146 V DC operating range.

• How many input channels are available on this module?

The 1746-IH16 provides 16 individual DC input points for monitoring field devices.

• What is the backplane current requirement of the module?

The module requires 85 mA from the 5 V DC SLC chassis backplane supply.

• Can the 1746-IH16 be installed in any PLC rack?

The module is designed specifically for compatible Allen-Bradley SLC 500 chassis configurations.

• Does the module support analog signal measurement?

No. The 1746-IH16 is a discrete digital input module and does not process analog values.

• What is the input signal delay specification?

The specified input signal delay time is 9 milliseconds for state change detection.

• What should be checked before replacing an existing module?

Verify the catalog number, voltage class, wiring arrangement, and controller configuration before replacement.

• Does the module require separate external power wiring?

The module uses the SLC chassis backplane supply for internal operation while field signals are connected through input terminals.