Introduction to the GE Fanuc IC670ALG230

The GE Fanuc IC670ALG230 is a high-performance, 8-point analog current input module belonging to the renowned Field Control series. GE Fanuc engineered this expansion module to work seamlessly with a compatible Bus Interface Unit (BIU), providing a bridge between field-level analog sensors and the central processing logic.

While the manufacturer has officially transitioned this product to “Discontinued” status, the IC670ALG230 remains a vital component for industrial facilities maintaining legacy GE Field Control systems. It offers a reliable solution for monitoring process variables such as pressure, temperature, and flow by converting standard industrial current signals into digital data for the host CPU.

Precision Signal Acquisition and Resolution

The IC670ALG230 features eight single-ended input channels. These channels support both 0-20 mA and 4-20 mA signal ranges, covering the vast majority of industrial transmitter outputs.

To ensure high data fidelity, the module utilizes an internal Analog-to-Digital Converter (ADC) with 12-bit digital resolution. This translates to an analog resolution of 5.0 µAmps, allowing the system to detect even minute fluctuations in the process loop. The module maintains an impressive hardware accuracy of ±0.05% of full scale at room temperature (25°C), ensuring that the data reaching your controller reflects the true state of the field environment.

High-Speed Conversion and Filtering

Speed is a critical factor in distributed I/O systems. The IC670ALG230 boasts a typical conversion time of just 60 microseconds per channel at a 1 MHz module clock. This rapid processing ensures that the Bus Interface Unit receives updated process values with minimal latency.

To protect the signal from electromagnetic interference (EMI) and high-frequency noise common in industrial plants, GE Fanuc integrated a 1st order RC input filter. This filter provides a typical transition capacity of 160 Hz, smoothing out transient spikes and ensuring that the control logic operates on clean, stable data.

Electrical Specifications and Isolation

The IC670ALG230 prioritizes system safety and signal integrity through robust electrical isolation.

• Isolation Ratings: The module provides 1500 VAC isolation for one minute (or 250 VAC continuous) between the ground and the logic circuits. It also features 250 VAC continuous isolation to the case.
• Input Impedance: The current loop utilizes a precision internal resistance, typically ranging from 249.75 to 250.25 Ohms.
• Power Requirements: The module operates on an external power supply range of 18-30 VDC (24 VDC nominal). It draws a maximum of 51 mA from the BIU power supply and up to 210 mA when including the full current loop.

Diagnostic Features and Fault Detection

Maintenance teams benefit from the built-in diagnostic capabilities of the IC670ALG230. The module includes open-wire detection and over-range fault detection. These features allow the system to identify physical wiring failures or sensor malfunctions immediately.

The front of the module features clear LED indicators. these LEDs provide real-time visual status of the backplane operation and the field power availability. This simplifies troubleshooting, as technicians can quickly verify if the module has power and is communicating correctly with the BIU without needing specialized diagnostic tools.

Application Scenarios

Industrial engineers typically deploy the IC670ALG230 in diverse automation environments, including:

1. Variable Frequency Drives (VFD): Monitoring speed or torque feedback signals.
2. Panel Meters and Data Loggers: Interfacing field measurements for local display and historical recording.
3. Signal Splitters: Receiving signals from multi-output transmitters.
4. Process Monitoring: Interfacing with pressure, level, and flow transmitters in chemical or water treatment facilities.

Environmental and Installation Guidelines

The IC670ALG230 features an open enclosure design, requiring installation within a protected control cabinet to prevent exposure to water or contaminants. It operates reliably in temperatures ranging from 0 to 60 degrees Celsius and handles up to 95% non-condensing humidity.

Proper grounding is essential for this module. GE Fanuc recommends a solid ground connection to enhance noise immunity and provide a stable reference point for all single-ended inputs. When using loop-powered transmitters, ensure they share the same power supply to maintain signal consistency across the channel group.

Conclusion: Reliable Legacy Support

Although the IC670ALG230 is an obsolete part, its robust design and 12-bit precision make it a highly sought-after component for system repairs and expansions. By choosing this module, you ensure the continued operation of your GE Field Control infrastructure with a part that meets original OEM specifications for accuracy, speed, and safety.