Overview of the GE Fanuc IC660BBA105 Genius I/O Block

The GE Fanuc IC660BBA105 is a high-performance, standalone analog output block designed for the Genius I/O distributed system. This module, originally manufactured by GE Fanuc and now supported under the Emerson Automation umbrella, provides six current-sourcing analog outputs. It serves as a critical interface for Series 90-30, Series Five, and Series Six PLC systems, converting digital control signals into precise analog currents to drive field actuators, valves, and recorders.

The IC660BBA105 stands out due to its “Genius” architecture, which allows for distributed intelligence. Unlike traditional I/O, this block communicates over a serial bus, reducing wiring costs and providing advanced diagnostics directly from the factory floor. Its robust design makes it suitable for demanding industrial environments where reliability and precision are paramount.

Technical Specifications and Performance

The IC660BBA105 delivers exceptional signal accuracy and resolution, ensuring tight control over industrial processes.

• Output Channels: Six (6) independent current-sourcing analog outputs.
• Signal Range: Operates primarily in the 4-20 mA range, though it can scale from 0 to 24 mA.
• Resolution: Features a fine 6 µA resolution, utilizing a 12-bit digital-to-analog converter (DAC).
• Accuracy: Maintains a high precision of 0.15% of full scale at 25°C.
• Update Rate: The block updates all six outputs every 25 ms, ensuring responsive control for dynamic systems.

The module handles power versatilely, accepting either 115 VAC (93-132V) or 125 VDC (105-145V). This flexibility allows engineers to integrate the block into various power infrastructures without needing additional transformers or converters.

Advanced Diagnostics and Safety Features

One of the primary advantages of the IC660BBA105 is its comprehensive diagnostic suite. The block continuously monitors its own health and the integrity of the connected loops.

1. Fault Reporting: The module detects and reports over-range and under-range signals. It specifically identifies feedback signals lower than 1.5 mA, indicating a potential loop failure.
2. Load Monitoring: It easily identifies no-load errors, overloads, and short-circuit conditions. These diagnostics prevent damage to the module and the connected field equipment.
3. Configurable States: In the event of a CPU error or communication loss, users can configure the block to “Hold Last State” or transition to a pre-defined “Default Value.” This feature is vital for maintaining process safety during system interruptions.
4. Redundancy Support: The IC660BBA105 supports CPU redundancy, ensuring that the analog outputs remain active even if the primary controller fails.

Wiring, Installation, and Mechanical Design

The IC660BBA105 features a 32-terminal strip for all field and power connections.

• Power Connections: Terminals 6 and 7 accept the main power source (115 VAC or 125 VDC).
• Output Wiring: Terminals 11 through 32 handle the six self-powered analog outputs.
• Serial Bus: Terminals 1-4 manage the Genius serial bus (Serial 1, Serial 2, Shield In, and Shield Out).
• Wire Gauges: For field signals, Honeywell recommends AWG #14 to #20. For the serial bus, AWG #12 is preferred for single wires, while AWG #22 is the minimum size allowed.

Mechanically, the block uses an open enclosure design intended for panel mounting. It measures 8.83″ high, 3.50″ wide, and 3.94″ deep. Installers should use 8-32 size screws and star washers to ensure a solid ground connection, which is essential for noise immunity and signal stability. The unit dissipates approximately 12 Watts of heat during normal operation, so adequate airflow within the enclosure is necessary to stay below the 60°C operating limit.

Compatibility and Configuration

The IC660BBA105 is a versatile component compatible with all Genius bus controllers. To configure the internal settings—such as scaling to engineering units or setting fault triggers—technicians use a Handheld Monitor (HHM) with version 3.7 or higher.

For software-based configuration, Logicmaster 6 (ver 4.02+) is the standard tool. The block integrates seamlessly with several GE Fanuc CPU generations:

• Series Six: Revision 105 or later.
• Series Six Plus: Revision 110 or later.
• Series Five: Revision 3.0 or later.
• Bus Switching: If your application requires a Bus Switching Module (BSM) for cable redundancy, the IC660BSM021 is the only compatible companion device.

Why Choose the IC660BBA105?

The GE Fanuc IC660BBA105 provides a reliable, high-precision solution for analog signal distribution. Its ability to source its own current loops eliminates the need for external loop power supplies, simplifying cabinet design. The combination of 12-bit resolution, 1500V block-to-block isolation, and sophisticated fault detection makes it an ideal choice for critical infrastructure in water treatment, power generation, and chemical processing. By utilizing the Genius protocol, you gain a level of diagnostic insight that standard analog modules simply cannot match.