GE IC693ALG223 Analog Current Input Module

Technical Specifications

• Number of Channels: 16 single-ended input channels

• Input Ranges: 4 to 20 mA (default), 0 to 20 mA, and 4 to 20 mA Enhanced

• Resolution: 12-bit resolution over the selected range

• Resolution Details:

  • 4 µA per bit for the 4 to 20 mA range

  • 5 µA per bit for the 0 to 20 mA and 4 to 20 mA Enhanced ranges

• Update Rate: 13 milliseconds for all 16 channels

• Absolute Accuracy:

  • ±0.25% of full scale at 25°C (77°F)

  • ±0.5% of full scale over the specified operating temperature range

• Linearity:

  • Less than 1 LSB from 4 to 20 mA for the 4 to 20 mA range

  • Less than 1 LSB from 100 µA to 20 mA for the 0 to 20 mA and Enhanced ranges

• Input Impedance: 250 ohms

• Input Filter Response: 19 Hz low pass filter

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

• Common Mode Voltage: 0 V (single-ended channels)

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

• External Power Supply: 20 to 30 VDC, with a maximum 10% supply voltage ripple

• Internal Power Consumption:

  • 120 mA from the +5 VDC backplane bus

  • 65 mA from the external 24 VDC user supply, exclusive of current loop currents

• Maximum Modules per System: Varies by CPU model; 4 modules with CPU311, 313, or 323; 8 with CPU331; 12 with CPU340 or 341; and 51 with CPU351 or 352

Key Functional Features

• Selectable Input Ranges: Each channel is configurable via software or a Hand-Held Programmer to operate in one of three modes. The standard 4-20 mA range maps 4 mA to a count of 0 and 20 mA to 32,000. The Enhanced 4-20 mA range maps 0 mA to a count of -8,000, 4 mA to 0, and 20 mA to 32,000, providing negative digital values for open-wire fault detection when current drops below 4 mA .

• Open-Wire Detection: The 4 to 20 mA Enhanced range gives users the capability to set a low alarm limit that detects when input current falls from 4 mA to 0 mA, enabling automatic open-wire fault detection in critical analog loops .

• Configurable Alarms: High and low alarm limits are available on all three ranges and can be configured on a per-channel basis, allowing customized warning thresholds for each connected field device .

• Status Reporting: The module reports both module health status and user-side power supply status to the CPU, with two green LED indicators—MODULE OK and USER SUPPLY OK—providing immediate visual diagnostics on the front panel .

• Robust Signal Integrity: With greater than 80 dB cross-channel rejection, a 19 Hz low-pass input filter, and 1500 V RMS isolation between the field and logic sides, the module delivers reliable signal acquisition even in electrically noisy environments .

Application Scenarios

• Process Control Industries: Deployed in chemical, petrochemical, and oil and gas facilities to interface with 4-20 mA transmitters measuring pressure, flow, temperature, and level. The open-wire detection feature is critical for identifying faulty sensor wiring before it leads to incorrect control actions .

• Water and Wastewater Treatment: Used in municipal and industrial treatment plants for monitoring flow rates, tank levels, and chemical dosing signals from field instruments across long cable runs, where 4-20 mA current loops provide superior noise immunity .

• Power Generation and Energy Management: Applied in power plants to acquire process variables from transmitters for boiler control, turbine monitoring, and balance-of-plant systems, integrating into SCADA and DCS architectures .

• Food and Beverage, Pulp and Paper Manufacturing: Installed on production lines where consistent, high-accuracy analog signal conversion is required for continuous process monitoring and batch control applications .