Allen-Bradley 1746-IO12DC SLC 500 Digital I/O Module

June 23, 2026 • 3 min read • wayne • Industry News

Product Summary

The 1746-IO12DC is a versatile digital I/O combination module for the SLC 500 system. It provides six 24V DC inputs and six relay contact outputs. Engineers use this module to bridge DC sensing with AC load control. This design saves valuable chassis space and reduces wiring complexity.

Product Procurement & Buyer Guide

Procurement managers need precise specs for system compatibility. The 1746-IO12DC operates on a voltage range of 10-30 Volts DC for inputs. It delivers six relay outputs that handle 5-265V AC and 5-125V DC loads. This flexibility makes it ideal for mixed-voltage control panels.

Application engineers value the module's robust current handling. Each output point supports 1.5 Amps at 120V AC. The same point manages 1.2 Amps at 24V DC. This allows direct control of small motors, valves, and indicator lights without external relays.

The module draws a backplane current of 60-80 milliamps. It dissipates only 3.9W of heat total. This low power consumption reduces thermal stress on your enclosure. It also keeps your power supply budget lean and efficient.

You must install the module in any SLC 500 chassis slot except slot 0. Slot 0 is reserved for the processor module. This placement rule ensures proper backplane communication and system stability.

The 1746-IO12DC offers NEMA ICS 2-230 noise immunity. This certification guarantees reliable operation in electrically noisy industrial environments. It also holds C-UL and CSA certifications for North American safety standards.

For harsh environments, the module operates from 0 to 60 °C. It survives non-operational storage from -40 to 85 °C. The unit withstands 30G of operational shock and 2.5G of vibration. These ratings ensure longevity on heavy machinery and conveyor systems.

Deep-Dive Technical FAQ

Question 1: What is the signal delay for the 1746-IO12DC outputs?

The relay outputs have a turn-on delay of 35 milliseconds. The turn-off delay is 45 milliseconds. This response time is suitable for material handling and packaging lines.

Question 2: Can I connect both AC and DC loads to the same module?

Yes, you can. The six inputs accept 10-30V DC signals. The six outputs are isolated relay contacts. You can switch 120V AC motors and 24V DC solenoids on the same unit.

Question 3: What is the maximum current per output point?

Each output point has a maximum current of 2 Amps. The rated continuous current is 1.5 Amps at 120V AC. The rating drops to 1.2 Amps at 24V DC due to contact heating.

Question 4: How do I calculate the total power dissipation?

The module dissipates 1.84W per active output point. The entire module dissipates 3.9W maximum. Use this value to size your enclosure ventilation and ambient temperature limits.

Question 5: Does the module require external fusing for the outputs?

Yes, you must fuse each output point externally. The relay contacts use a Normally-Open configuration. A 2 Amp fast-blow fuse protects the contact from short circuits and overloads.