The Allen-Bradley 1794-ASB2 is a compact Remote I/O (RIO) adapter module designed for the FLEX I/O 1794 platform. This adapter serves as a communication interface node, enabling the connection of up to two local FLEX I/O modules to a master programmable controller via the Allen-Bradley RIO network. It is specifically optimized for low-density, distributed automation tasks, such as remote valve control, operator interface stations, and compact machinery sub-panels.

Features

• Compact Architecture: Supports a 2-slot configuration, providing a space-efficient solution for small-scale I/O requirements.
• Network Compatibility: Utilizes standard Allen-Bradley Blue Hose coaxial media for reliable communication on RIO networks.
• Selectable Baud Rates: Supports communication speeds of 57.6 Kbps, 115.2 Kbps, and 230.4 Kbps to match existing system requirements.
• Robust Power Management: Converts 24 VDC input to a regulated 5 VDC backplane supply, providing up to 640 mA for attached modules.
• Industrial Hardening: Engineered with high immunity to Electrical Fast Transients (EFT) and surges up to 2 kV, along with 8 kV ESD protection and 10 V/m RF field immunity.

Applications

The 1794-ASB2 is ideal for decentralized plant floor applications where limited I/O points are required at a specific location. Common use cases include localized control of pneumatic valve nests, remote push-button stations, and small-footprint machine control panels that require integration into a larger RIO network architecture.

Technical Specifications

Installation Guidelines

• Ensure the power is disconnected before installing or removing the module from the DIN rail or terminal base.
• Mount the module in a clean, dry environment; the unit is an open-style device and requires an appropriate enclosure for protection against contaminants.
• Use shielded Blue Hose cable for RIO network connections to minimize electromagnetic interference.
• Maintain proper grounding practices to prevent ground loops; ensure the chassis ground is connected to a low-impedance earth ground.
• Verify that the external 24 VDC power supply is within the specified 19.2 to 31.2 VDC range before applying power.

FAQ

Q: Can I use this module with more than 2 I/O modules?
A: No, the 1794-ASB2 is specifically designed to support a maximum of 2 functional FLEX I/O modules.

Q: What is the primary communication medium for this adapter?
A: This module is designed for use with Allen-Bradley Blue Hose coaxial cable.

Q: Is this module suitable for high-vibration environments?
A: While robust, it is an open-style module. Ensure it is mounted securely on a 35 mm DIN rail or panel within an enclosure rated for the specific industrial environment.