The Allen-Bradley 1746-OB32, also cataloged as the 1746-OB32 Digital Output Module, operates as a dedicated hardware component for 32-point transistor source output execution within the SLC 500 control platform.

Model Identification

The 1746-OB32 is an SLC 500 series digital output module designed for DC sourcing applications. It provides 32 transistor-based output channels with a 5 to 50 VDC output range. The module interfaces with the SLC 500 backplane and transfers CPU commands into discrete electrical switching signals.

Hardware Specifications

PLC Backplane and I/O Configuration

The 1746-OB32 uses SLC 500 backplane communication for data exchange between the processor and output circuits. The module receives discrete output commands from the controller and activates external DC loads through transistor switching channels.

The SLC 500 platform supports modular I/O density scaling, allowing digital output expansion through chassis-based module installation. Proper module addressing and slot configuration are required during controller programming.

The output circuit design provides separate commons for groups of channels, reducing wiring complexity for multi-load DC control applications.

Ordering Information

• 1 x Allen-Bradley 1746-OB32 SLC 500 Digital Output Module
• Module identification label included
• Factory-installed terminal interface included
• No additional programming software or controller hardware included

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 position matches the configured controller I/O address.

Wiring Requirements

• Use appropriate DC-rated wiring according to connected load current.
• Separate high-current output wiring from low-level communication wiring.
• Connect field devices according to sourcing output polarity requirements.
• Check terminal connections before applying chassis power.

Grounding and Noise Control

• Maintain proper cabinet grounding practices.
• Route DC output wiring away from high-noise switching equipment.
• Use shielding methods when installed near electromagnetic interference sources.

Frequently Asked Questions

• Is the 1746-OB32 a relay output module?

  No. The 1746-OB32 is a transistor source output module designed for DC switching applications.

• How many output channels are available?

  The module provides 32 digital output points arranged for SLC 500 discrete control applications.

• What voltage range does the module support?

  The specified output range is 5 to 50 VDC for transistor source switching.

• What is the maximum module current rating?

  The module current rating is specified as 8 A total across the output assembly.

• What backplane current does the module require?

  The module requires 190 mA from the SLC 500 chassis 5 VDC backplane supply.

• Can the module be installed while powered?

  Installation should follow SLC 500 chassis procedures. Power removal is recommended before module replacement.

• What type of field devices can be connected?

  The module can control compatible DC loads requiring sourcing transistor output signals.

• Does the module support firmware upgrades?

  The module does not contain user-upgradable firmware. Operation depends on SLC 500 controller configuration.