Overview
The Allen-Bradley 1794-IB8 is a Series A 8-point digital input module from the Rockwell Automation FLEX I/O (Bulletin 1794) platform. It is a Flex 1794 digital DC input module that mounts onto a terminal base unit, which makes the connection between the field devices and the I/O bus, and because the module itself has no direct field wiring it can be inserted or removed under power to reduce system restart time. Rockwell Automation currently lists the 1794-IB8 with an Active Mature lifecycle status, so it remains supported for sustaining existing installations.
Key Features
- 8 sinking digital inputs rated for 24V DC field devices
- 10–31.2V DC on-state voltage range with 1.5 mA minimum off-state current and 3.5 W maximum power dissipation at 31.2V DC
- Mounts on a 1794 terminal base unit so modules can be removed under power without disturbing field wiring
- Works with ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O FLEX adapters
- Per-channel yellow LED status indicators for fast troubleshooting
- DIN rail mounting for standard FLEX I/O panel layouts
Technical Specifications
Verified specifications for the Allen-Bradley 1794-IB8 FLEX I/O digital input module are listed in the specs table below. Ratings reference the Rockwell Automation 1794-IN093 installation instructions and authorized distributor listings.
Typical Applications
The 1794-IB8 is commonly used to acquire discrete 24V DC signals from proximity sensors, photoelectric sensors, limit switches, pushbuttons, and contact closures in distributed I/O architectures. Typical use cases include conveyor and packaging lines, material handling, water/wastewater pump stations, OEM machine builds, and remote skid-mounted equipment where FLEX I/O drops keep field wiring close to the sensors.
Compatibility & Replacements
The Allen-Bradley 1794-IB8 installs onto standard FLEX I/O terminal base units. Compatible terminal base units include the 1794-TB3 and 1794-TB3S. The module communicates back to the controller through any FLEX I/O communication adapter — ControlNet, DeviceNet, EtherNet/IP, and Universal Remote I/O are all supported. It is programmed and configured in RSLogix 5000 or Studio 5000 Logix Designer as part of the FLEX I/O tree. For extreme-temperature installations, Rockwell offers the FLEX I/O-XT family as an alternative; FLEX I/O-XT modules are rated for -20…70 °C (-4…158 °F) and are compatible with the ControlLogix-XT extreme environment system.
