Allen-Bradley 1797-BIC | FLEX Ex Bus Isolator Module

Product Description

Overview

The Allen-Bradley 1797-BIC (Part Number: 1797-BIC) is a specialized Bus Isolator Coupler designed for the FLEX Ex™ I/O system. It provides galvanic isolation and intrinsic safety for ControlNet communication, enabling high-speed digital signals to traverse safely between standard “Safe Area” networks and hazardous areas (Zone 1/Division 1). This module ensures that electrical faults, surges, or transients on one segment do not compromise the safety or operation of devices on another segment.

Core Features

• Electrical Isolation: Provides high-level galvanic isolation, preventing high-voltage transients or ground faults from affecting connected devices.

• Intrinsic Safety: Limits voltage and current to levels safe for explosive atmospheres, compliant with ATEX, IECEx, UL, and CSA standards.

• Seamless ControlNet Integration: Supports 5 Mbps high-speed ControlNet communication without requiring a dedicated node address, maintaining full network transparency.

• Compact Modular Design: Fits standard FLEX I/O footprint and requires the 1797-PS power supply for operation.

• Diagnostic Indicators: Equipped with LEDs to display power and network link status for rapid fault identification.

Performance Characteristics

1. Hazardous Area Compatibility

Engineered to bridge standard and intrinsically safe networks, the 1797-BIC allows digital signals to enter hazardous zones safely, eliminating the need for bulky explosion-proof enclosures for each I/O module.

2. Robust Communication

Supports full ControlNet throughput of 5 Mbps while isolating electrical disturbances. Maintains signal integrity in high EMC or electrically noisy environments.

3. Galvanic Isolation

High-level isolation between the FLEX Ex™ backplane and ControlNet network prevents ground loops and protects the system from surges or faults originating in field devices.

4. Environmental Durability

• Operating Temperature: -20°C to +70°C

• Protective Coating: Conformal coating ensures resistance against chemical exposure, corrosion, and harsh industrial conditions.

Technical Specifications

Key Application Benefits

• Extends high-speed ControlNet communication into hazardous zones safely.

• Reduces installation cost by avoiding individual explosion-proof enclosures for each I/O.

• Maintains system reliability by isolating electrical faults and surges from sensitive control devices.

• Simplifies maintenance with status LEDs for immediate troubleshooting.

FAQ

Q: Can the 1797-BIC be installed in Zone 1 hazardous areas?
A: Yes, it is designed to provide intrinsically safe outputs for Zone 1/Division 1 while the input resides in a Safe Area or Zone 2/Division 2.

Q: Does it require a special ControlNet configuration?
A: No, it operates transparently on the ControlNet network without a unique node address.

Q: What power supply is needed?
A: A 1797-PS FLEX Ex™ power supply is required, providing 18–32 V DC.

Q: How does it handle electrical surges?
A: Galvanic isolation and intrinsic safety circuitry protect connected devices from high-voltage spikes or ground faults.