Allen Bradley 1746-IO12DC SLC 500 Digital 24V DC Combination I/O Module

Technical Overview

The 1746-IO12DC (Part Number 1746-IO12DC) is a versatile digital combination module engineered for the SLC 500 platform. This unit provides a cost-effective solution for systems requiring a low density of both inputs and outputs within a single chassis slot. By integrating six sinking inputs and six relay outputs, the 1746-IO12DC (1746-IO12DC) optimizes rack space and is ideal for small-scale automation tasks where a dedicated input or output module would be underutilized.

This module interfaces seamlessly with the SLC backplane, offering reliable signal processing with a standard 8ms filter delay to mitigate electrical noise. The output section features mechanical relays, providing the flexibility to switch a variety of AC and DC voltages, making the 1746-IO12DC (1746-IO12DC) a preferred choice for controlling solenoids, small motor starters, and status indicators in distributed control architectures.

Technical Specifications

• Module Configuration Combination Digital Input/Output

• Input Channels 6 (24V DC Sinking)

• Output Channels 6 (Relay Contacts)

• Operating Voltage Range 10V to 30V DC

• Signal Delay 8 milliseconds (On and Off states)

• Continuous Current per Output 1.2A at 24V DC or 1.5A at 120V AC

• Backplane Current Draw 60mA at 5V DC and 80mA at 24V DC

• Isolation Voltage 1500V AC (between I/O and backplane)

• Connection Type Removable Terminal Block (1746-RT25)

• Operating Temperature 0 to 60 °C (32 to 140 °F)

• Physical Weight 1.00 lbs (0.45 kg)

Key Functional Features

The 1746-IO12DC (Part Number 1746-IO12DC) is designed for high-reliability industrial environments

• Space-saving design combines two functions into a single-slot footprint to reduce SLC 500 rack requirements.

• Mechanical relay outputs provide electrical isolation and the ability to control diverse load types without specialized interface circuitry.

• Integrated status LEDs provide immediate visual feedback for each I/O point to simplify troubleshooting and maintenance.

• Rugged construction ensures stable performance in high-vibration applications typical of industrial machinery.

Technical FAQ

Can the relay outputs on this module handle different voltages simultaneously?Yes, since the 1746-IO12DC (1746-IO12DC) uses mechanical contacts, each isolated common group can be wired to different voltage levels, such as 24V DC for some loads and 120V AC for others, within the rated specifications.

Does this module require an external 24V DC power source?The inputs require an external power supply to sense field device states. The relay coils are powered by the SLC backplane, but the switched load power must be provided externally.

What is the life expectancy of the relay contacts?The electrical life depends on the load current and frequency of operation. For standard inductive loads at rated current, the mechanical life typically exceeds millions of cycles.