GE IC693ALG221 4-Channel Analog Current Input Module

Technical Specifications

• Manufacturer: GE Fanuc / Emerson

• Product Type: Analog Current Input Module

• Series: Series 90-30 / PACSystems RX3i

• Number of Channels: 4 single-ended current inputs

• Input Ranges: 4-20 mA (default) or 0-20 mA (jumper-selectable)

• Resolution: 12-bit

• Resolution Detail: 4 µA per LSB (4-20 mA range); 5 µA per LSB (0-20 mA range)

• Update Rate: 2 milliseconds for all 4 channels (0.5 ms per channel conversion)

• Absolute Accuracy: 0.1% full scale + 0.1% reading

• Linearity: Less than 1 LSB (Least Significant Bit)

• Input Impedance: 250 Ω

• Isolation: 1500 V RMS between field side and logic side

• Common Mode Voltage: 200 V maximum

• Common Mode Rejection: Greater than 70 dB at DC and 60 Hz

• Cross-Channel Rejection: Greater than 80 dB from DC to 1 kHz

• Input Filter Response: 325 Hz (-3dB)

• Power Consumption from Backplane: 25 mA from +5V DC; 100 mA from isolated +24V DC

• Data Format: 16-bit 2’s complement in %AI registers

• Operating Temperature: 0°C to +60°C (32°F to 140°F)

• Storage Temperature: -40°C to +85°C (-40°F to +185°F)

• Humidity: 5% to 95% non-condensing

Functional Features

• Two Jumper-Selectable Input Ranges: Operates with a default input range of 4-20 mA. Installing a jumper on the terminal block changes the range to 0-20 mA. Two jumpers are provided—one for channel pair 1-2 and another for channel pair 3-4—enabling independent configuration of each pair .

• Precision Analog-to-Digital Conversion: Each input channel converts a current signal into a digital value through a 250 Ω precision shunt resistor followed by a 12-bit successive-approximation ADC. The conversion time is 0.5 ms per channel for a total scan cycle of 2 ms across all four channels .

• Digital Data Scaling: For the 4-20 mA range, 4 mA corresponds to a count of 0 and 20 mA corresponds to a count of 32,000 (1,000 counts = 0.5 mA). For the 0-20 mA range, 0 mA corresponds to a count of 0 and 20 mA corresponds to 32,000 (800 counts = 0.5 mA) .

• Optical Isolation: Data transmission between the field side and the logic side occurs across an optical isolation barrier, providing 1500 V RMS separation. This design prevents ground loops and blocks common-mode noise from corrupting PLC logic .

• Embedded Diagnostics: The module includes diagnostic circuitry for power-good monitoring, open-circuit detection (flagging current below 4 mA in 4-20 mA mode), and overrange detection (flagging input exceeding 21 mA). A front panel LED indicator illuminates during normal operation .

• Transient Protection: Input protection circuitry can withstand up to 200 V common-mode without damage, allowing reduced-performance operation during transient events .

Application Scenarios
This module is deployed across various industrial sectors where reliable acquisition of analog current signals is essential for process automation:

• Chemical Processing: Reads 4-20 mA signals from flow transmitters, pressure transducers, and temperature sensors in reactor vessels and pipeline monitoring systems .

• Pulp and Paper Manufacturing: Monitors stock flow, headbox pressure, and dryer temperatures using standard 2-wire transmitters in paper production lines .

• Oil and Gas Operations: Interfaces with pressure transmitters on separation trains, valve position feedback devices, and tank level transmitters on offshore platforms and refineries .

• Power Generation: Collects data from turbine bearing temperature transmitters, boiler drum level sensors, and steam flow measurement devices to support turbine-generator control .

• Water and Wastewater Treatment: Acquires signals from water quality analyzers, flow meters, and pressure sensors for process monitoring and chemical dosing control.

• General Manufacturing: Supports data acquisition from any field device with a standard 4-20 mA current loop output, including temperature, pressure, flow, and level instrumentation.

Important Clarification on Search Results
The search results for IC693ALG221 show significant contradictions across third-party distributor websites. The technical specifications presented above are drawn from the most consistent and authoritative available sources, which uniformly describe this as a 4-channel analog current input module for Series 90-30 PLCs with 12-bit resolution and 250 Ω input impedance . Several other sources contain conflicting data, including claims of 8 channels , voltage input capability (-10V to +10V) , 16-bit resolution , or 0.5 ms sampling rate . These discrepancies highlight the importance of referencing official GE documentation when precise specifications are required for system integration.