Overview
The Allen-Bradley 1791D-0B16PX is a CompactBlock I/O DeviceNet expansion block delivering 16 sourcing-type 24VDC outputs. Part of the proven CompactBlock I/O series, this Series D module provides flexible I/O expansion for distributed automation and industrial control networks. Designed for DIN rail mounting, it connects to compatible base modules via ribbon cable and integrates directly with DeviceNet master controllers, SLC 500, PLC-5, or SoftLogix programmable controllers using DeviceNet scanners.
Key Features
- 16 sourcing-type 24VDC output channels organized in two groups of eight
- DeviceNet communication with support for 125 Kbps, 250 Kbps, and 500 Kbps data rates
- Flexible connection modes: cyclic, polled, and change-of-state messaging
- DIN rail mounting (panel mounting not supported per manufacturer specifications)
- Built-in LED status indicators for Mod/Net, Logic, and I/O status monitoring
- Expansion power rated at 5V DC / 100 mA; auxiliary power 10–30V DC / 4A maximum
- IEC IP20 enclosure rating
Technical Specifications
- Output Type: 16-point sourcing (2 groups of 8)
- Output Voltage: 24 VDC nominal
- Expansion Power: 5V DC @ 100 mA
- Auxiliary Power: 10–30V DC, 4A maximum
- Isolation Requirement: 500V AC when linked to DeviceNet
- Communication Protocol: DeviceNet (125 Kbps @ 500m, 250 Kbps @ 200m, 500 Kbps @ 100m on Thick cable)
- Data Exchange Modes: Cyclic, polled, or change-of-state
- Enclosure Type: IEC IP20
- Mounting: DIN rail (required)
- I/O Byte Consumption: Varies by base module configuration (1–4 output bytes when stacked)
- Series: CompactBlock I/O 1791D (Series D)
Typical Applications
- Distributed I/O stations on DeviceNet networks
- Machine control and automation panels requiring remote output expansion
- Process industries with modular, scalable PLC architectures
- System integrations demanding flexible, real-time discrete output control
- Retrofit projects upgrading legacy CompactBlock I/O systems
Compatibility & Replacements
Compatible With
- Allen-Bradley PLC-2, PLC-3, and PLC-5 series
- Allen-Bradley SLC 500 with DeviceNet adapter
- SoftLogix programmable controllers via DeviceNet scanners
- Any DeviceNet master supporting cyclic, polled, or change-of-state messaging
- CompactBlock I/O base modules (input, output, or combination types)
- DeviceNet thick or flat cable media
Replaces / Drop-In Replacement For
- Earlier CompactBlock I/O 1791D output expansion modules (where Series D compatibility is confirmed)
- Verify compatibility with your system integrator before ordering, as module stacking configuration and control program requirements vary by application.
Works With
- DeviceNet communication protocol and standard DeviceNet scanners
- CompactBlock I/O configuration and control software
- Studio 5000 Logix Designer (for connected PLC-5 / SLC 500 systems via appropriate gateways)
- RSLogix 5 and RSLogix 500 for legacy platform programming
- Cyclic, polled, or change-of-state connection modes selectable via scanner configuration
















