Allen-Bradley 1746-IG16 SLC 500 Current Sourcing TTL Input Module

Description

The Allen-Bradley 1746-IG16 is a specialized current sourcing Transistor-Transistor Logic (TTL) input module designed specifically for the Allen-Bradley SLC 500 modular controller platform. As a chassis-located component, this single-slot module efficiently interfaces with electronic devices that require precise 5VDC TTL signal monitoring. It integrates seamlessly into standard SLC 500 backplanes, excluding processor slot 0, to deliver reliable discrete data acquisition in demanding industrial automation environments.

Engineered for high-speed performance, the 1746-IG16 minimizes signal delay to ensure rapid response times across its 16 available input channels. The module processes low-voltage DC signals while maintaining robust electrical isolation between the field devices and the controller backplane. Proper handling procedures, including grasping the unit by its ends rather than exposed metallic surfaces, safeguard the internal circuitry against electrostatic discharge during installation and maintenance.

Features

• Provides 16 current sourcing TTL input channels tailored for 5VDC logic compatibility.
• Designed for direct integration into any available I/O slot (except slot 0) of an Allen-Bradley SLC 500 chassis.
• Features ultra-low signal delay for fast processing, with a maximum ON delay of 0.25 ms and OFF delay of 0.50 ms.
• Consumes minimal backplane power, drawing 0.140A at 5VDC and 0.0A at 24VDC.
• Equipped with built-in tolerance for up to 50 mV peak-to-peak voltage ripple on the input power supply.

Applications

• Interfacing with TTL-compatible microprocessors, instruments, and custom electronic hardware.
• High-speed discrete event logging and monitoring within SLC 500 automation networks.
• Data acquisition systems requiring low-voltage DC signal integration.
• Legacy machine control upgrades and maintenance replacements.

Technical Specifications

Connections / Interfaces

The 1746-IG16 module features a removable terminal block (RTB) located on the front of the unit, allowing for secure field wiring connections without disturbing module electronics. The internal circuitry connects directly to the SLC 500 backplane via an edge connector, establishing communication and power delivery with the central processor and power supply.

Installation Guidelines

• Power off the SLC 500 chassis before inserting or removing the 1746-IG16 module to prevent electrical arcing and equipment damage.
• Observe proper electrostatic discharge (ESD) precautions by wearing a grounded wrist strap and handling the module by its molded plastic housing edges.
• Align the module with the card guides of the desired chassis slot (slots 1 through 30 depending on chassis size, avoiding slot 0) and push firmly until the top and bottom latches secure it in place.
• Connect field wiring to the removable terminal block in accordance with the system wiring diagrams, ensuring proper polarity for current sourcing operation.