I/O modules

This analog current input module converts 4–20 mA signals from field transmitters into digital values for the controller. It provides accurate process monitoring for pressure, flow, and level measurements. The IC694ALG221 offers eight isolated input channels in a single-slot format.

Core Input Specifications

The module accepts eight analog current inputs from two-wire or four-wire field devices. Each channel delivers 16-bit resolution for precise measurement across the full span. Furthermore, the unit provides a built-in 24 V DC loop power supply for two-wire transmitters. The module achieves an accuracy of ±0.1% of full scale at 25°C. It supports input ranges of 0–20 mA and 4–20 mA for flexible device compatibility.

Connectivity and Channel Features

The front panel houses two 10-pin terminal blocks for all current input connections. These blocks accommodate solid or stranded wires from 0.2 to 1.5 mm². Additionally, the IC694ALG221 includes individual channel status LEDs for quick fault identification. A green LED indicates normal operation while a red LED signals an open-circuit condition. Engineers can configure each channel independently using software commands.

Data Integrity and Noise Rejection

An integrated analog filter suppresses 60 Hz noise on every input channel effectively. This filter ensures stable readings in electrically noisy industrial environments. Furthermore, the IC694ALG221 provides 500 V DC isolation between channels and the backplane. The unit includes an overcurrent protection circuit that limits input current to 30 mA. It also features a self-calibration routine that compensates for temperature drift automatically.

Mechanical Specifications and Environmental Ratings

The module measures 22.5 x 14.0 x 4.0 centimeters and weighs approximately 550 grams. Its compact design occupies a single slot in GE RX3i standard racks. The operating temperature range spans 0°C to +60°C with 95% non-condensing humidity tolerance. Moreover, the IC694ALG221 features gold-plated edge connectors for reliable backplane interfacing.

Technical Parameters Summary

System Integration and Application Areas

This input module integrates seamlessly with GE RX3i controllers and expansion racks. It communicates with the CPU through the backplane for high-speed data transfer. The unit’s loop power capability simplifies wiring for two-wire pressure and temperature transmitters. Process industries such as chemical plants, water treatment, and pharmaceutical manufacturing benefit from its precision.

Summary

The IC694ALG221 provides reliable and accurate analog current input for process automation. Its high resolution, built-in loop power, and diagnostic feedback ensure dependable operation. This module offers an excellent solution for multi-channel current measurement needs.

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