GE Fanuc IC694 Modules - IC694ALG392-FG

Technical Dossier

Product Details And Specifications

GE Fanuc IC694 Series Technical Notes

The GE Fanuc IC694 series — the hardware backbone of the Series 90-30 programmable logic controller platform — holds a dominant installed base across global heavy industry. Refineries in the Middle East, chemical processing plants in Europe, and nuclear auxiliary systems in North America continue to operate on IC694 infrastructure commissioned in the 1990s and 2000s. The platform's modular rack architecture, deterministic scan cycle, and broad I/O density made it the default choice for mid-range process automation for over two decades. As of 2026, the IC694 series is classified as mature/end-of-life by GE Vernova (formerly GE Digital / GE Fanuc Automation), with no new hardware development. Long-term maintenance support is now the primary operational concern for asset owners.

The Evolution of IC694 Architecture

The IC694 designation identifies the Series 90-30 PLC hardware generation, introduced by GE Fanuc Automation in the early 1990s as a successor to the Series Six and Series Five platforms. The architecture is built around a passive backplane (5-slot: IC694CHS392, 10-slot: IC694CHS398) with a proprietary bus that carries both power and data. CPUs communicate with I/O modules via this internal bus at fixed scan rates, with no fieldbus dependency for local I/O — a design that prioritized determinism over flexibility.

The first-generation CPUs (IC694CPU311, IC694CPU313) offered limited memory and no Ethernet-native capability. Mid-generation revisions introduced the IC694CPU364 and IC694CPU374, adding embedded Ethernet ports and expanded program memory (240KB to 512KB). The final CPU generation — IC694CPU374 — supports EGD (Ethernet Global Data) and SRTP protocols, enabling integration with SCADA systems without a dedicated communications coprocessor.

Compatibility constraints are significant: IC694 modules are not directly interchangeable with the IC693 (Series 90-30 earlier revision) or the IC695 (PACSystems RX3i) platforms without adapter hardware or full rack replacement. Firmware versions on CPUs must be matched to the Proficy Machine Edition (PME) programming software version used for project maintenance. Mixing IC694 and IC693 modules in the same rack is not supported.

IC694 Full Catalog & Functionalities (SKU List)

CPU Modules

• IC694CPU311: Series 90-30 CPU, 6KB user memory, no Ethernet, basic ladder logic execution.
• IC694CPU313: Series 90-30 CPU, 12KB user memory, supports function block and structured text.
• IC694CPU323: Series 90-30 CPU, 16KB memory, enhanced instruction set for motion sequencing.
• IC694CPU340: Series 90-30 CPU, 32KB memory, supports floating-point math operations.
• IC694CPU350: Series 90-30 CPU, 32KB memory, high-speed interrupt inputs, expanded I/O scan.
• IC694CPU364: Series 90-30 CPU with embedded 10/100 Ethernet, 240KB memory, SRTP/EGD support.
• IC694CPU374: Series 90-30 CPU, 512KB memory, dual Ethernet ports, highest-spec IC694 CPU.

Analog I/O Modules

• IC694ALG220: 4-channel analog input, 4–20mA / 0–10V, 12-bit resolution.
• IC694ALG221: 8-channel analog input, current/voltage selectable per channel, 12-bit.
• IC694ALG222: 16-channel analog input, high-density current/voltage, 12-bit resolution.
• IC694ALG390: 2-channel analog output, 4–20mA / 0–10V, 12-bit DAC.
• IC694ALG391: 4-channel analog output, current/voltage selectable, 12-bit DAC.
• IC694ALG392-FG: 8-channel analog output, 4–20mA / 0–10V, 12-bit DAC, field-installable conformal coating variant (-FG suffix).
• IC694ALG442: 4-channel analog input, high-resolution 15-bit, thermocouple/RTD compatible.

Digital I/O Modules

• IC694MDL330: 8-point 120VAC discrete input module, isolated, standard density.
• IC694MDL340: 16-point 120VAC discrete input module, non-isolated, high density.
• IC694MDL390: 8-point 120VAC discrete output module, relay contact, 2A per point.
• IC694MDL740: 16-point 24VDC discrete input module, sink/source selectable.
• IC694MDL741: 32-point 24VDC discrete input module, high-density, 0.5ms filter.
• IC694MDL752: 16-point 24VDC discrete output module, sourcing, 0.5A per point.
• IC694MDL753: 32-point 24VDC discrete output module, high-density sourcing output.

Power Supply Modules

• IC694PWR321: 120/240VAC input power supply, 30W output, standard rack supply.
• IC694PWR330: 120/240VAC or 125VDC input power supply, 30W, redundancy-capable.
• IC694PWR331: 24VDC input power supply, 30W, for DC-powered panel installations.

Communications Modules

• IC694CMM302: Serial communications coprocessor, RS-232/RS-485, supports SNP/SNPX protocols.
• IC694CMM321: Ethernet interface module, 10BaseT, for CPUs without embedded Ethernet.

Sourcing Hard-to-Find & Obsolete IC694 Parts

For end-users operating Series 90-30 systems beyond their original design life, DriveKNMS provides: direct replacement modules for failed units, tested spare sets for critical I/O racks, and cross-reference support for identifying equivalent modules where direct replacements are unavailable. Customers managing multi-site IC694 installations are encouraged to submit consolidated parts lists for bulk availability checks.

Quality Control for the IC694 Range

IC694 modules present specific test challenges due to their proprietary backplane bus protocol and the age-related failure modes common in legacy PLC hardware. DriveKNMS applies the following verification procedures to all IC694 inventory:

• Backplane bus communication test: each module is seated in a live IC694 rack and polled by a reference CPU to confirm bus arbitration and register read/write integrity.
• Analog channel calibration verification: all IC694ALG analog modules are tested across the full 4–20mA and 0–10V ranges using calibrated signal sources and measurement equipment. Channel-to-channel isolation is verified.
• Digital I/O point-level test: each discrete input and output point is individually exercised. Relay output modules are tested for contact resistance and switching cycle count.
• Power supply load test: IC694PWR units are tested under rated load for thermal stability and output voltage regulation.
• Firmware version logging: CPU modules are powered and firmware revision is recorded. Customers are advised of the firmware version prior to shipment to ensure PME software compatibility.
• Visual and physical inspection: conformal coating condition (-FG variants), capacitor condition, connector pin integrity, and label legibility are assessed on all units.