GE Fanuc Series 90-30 Modules: IC693CPU351

Technical Dossier

Product Details And Specifications

GE Fanuc Series 90-30 Technical Notes

The GE Fanuc Series 90-30 (also referenced as the 90-30 PLC or IC693 series) is one of the most widely deployed programmable logic controller platforms in global heavy industry. Installed across petrochemical refineries, nuclear power auxiliary systems, chemical processing plants, pulp and paper mills, and water treatment facilities, the Series 90-30 established a benchmark for modular, rack-based PLC architecture throughout the 1990s and 2000s. Its distributed I/O capability, deterministic scan cycle, and broad third-party integration support made it the default control platform for mid-scale automation projects requiring high channel density and multi-rack expansion.

The IC693CPU351 is a central processing unit module within this family, operating at 32-bit architecture with support for up to 12 racks, 2048 discrete I/O points, and 512 analog I/O channels. It executes ladder logic, function block, and structured text programs stored in battery-backed SRAM, with optional flash memory backup. The CPU351 communicates via the Series 90-30 backplane bus and supports Ethernet, SNP, and serial protocols through dedicated communications coprocessors.

The Evolution of Series 90-30 Architecture

The Series 90-30 platform was introduced by GE Fanuc Automation in the early 1990s as a successor to the Series Six and Series Five PLC families. The initial release centered on the IC693CPU311 and IC693CPU321, offering 6K and 12K word program memory respectively, with a 5-slot or 10-slot rack configuration. These early CPUs used a proprietary backplane bus operating at 8 MHz and supported only serial SNP communications.

The mid-generation refresh introduced the IC693CPU340 and IC693CPU350, expanding program memory to 240K words and adding support for the Ethernet Interface Module (IC693CMM321). This era also introduced the Genius Bus Controller (IC693BEM331), enabling distributed I/O over the Genius fieldbus at up to 153.6 Kbps — a critical capability for large-scale plant floor integration.

The IC693CPU351 represents the mature generation of the platform, with 512K word program memory, hardware floating-point support, and compatibility with the full IC693 I/O module library. Later variants including the IC693CPU360 and IC693CPU374 added embedded Ethernet ports and expanded data table sizes, bridging the Series 90-30 toward the PACSystems RX3i transition. GE Fanuc formally announced the migration path to the IC695 (PACSystems RX3i) platform in the mid-2000s, though Series 90-30 hardware remained in active production and support through 2015, with extended lifecycle support continuing beyond that date.

Compatibility note: Series 90-30 I/O modules are not electrically or mechanically interchangeable with PACSystems RX3i modules. Migration requires rack replacement, re-wiring, and program conversion using Proficy Machine Edition software.

Series 90-30 Full Catalog & Functionalities (SKU List)

CPU Modules

• IC693CPU311: 6K word CPU, 5-slot rack, SNP serial only, entry-level control
• IC693CPU321: 12K word CPU, multi-rack support, SNP/SNPX protocol
• IC693CPU340: 240K word CPU, floating-point math, expanded data tables
• IC693CPU350: 240K word CPU, enhanced instruction set, Genius bus support
• IC693CPU351: 512K word CPU, hardware float, full IC693 I/O compatibility
• IC693CPU360: Embedded Ethernet port, 512K word, dual-port memory
• IC693CPU374: High-speed CPU, 512K word, embedded Ethernet, advanced motion

Discrete Input Modules

• IC693MDL230: 8-point 120VAC discrete input, isolated, DIN rail compatible
• IC693MDL240: 16-point 120VAC discrete input, standard density
• IC693MDL241: 16-point 24VDC discrete input, positive logic, fast response
• IC693MDL260: 32-point 24VDC discrete input, high-density, grouped commons

Discrete Output Modules

• IC693MDL310: 8-point relay output, 2A per point, Form C contacts
• IC693MDL330: 8-point 120VAC triac output, isolated, 0.5A per point
• IC693MDL340: 16-point 120VAC output, standard density
• IC693MDL752: 32-point 24VDC output, high-density, sourcing

Analog I/O Modules

• IC693ALG220: 4-channel analog input, 4–20mA / 0–10V, 12-bit resolution
• IC693ALG390: 4-channel analog output, 4–20mA / 0–10V, 12-bit resolution
• IC693ALG442: 8-channel analog input, high-resolution, thermocouple/RTD capable

Communications & Network Modules

• IC693CMM321: Ethernet Interface Module, 10BaseT, TCP/IP, SRTP protocol
• IC693BEM331: Genius Bus Controller, master/slave, 153.6 Kbps fieldbus
• IC693CMM302: Serial Communications Module, RS-232/RS-485, ASCII/RTU

Power Supply Modules

• IC693PWR321: 120/240VAC input power supply, 30W output, standard rack
• IC693PWR330: 24VDC input power supply, 30W, for DC-powered panels

Sourcing Hard-to-Find & Obsolete Series 90-30 Parts

DriveKNMS maintains a dedicated inventory of Series 90-30 modules sourced through verified industrial surplus channels, decommissioned plant equipment, and long-term stocking agreements. All units are cataloged by part number, firmware revision, and hardware revision level. For CPU modules such as the IC693CPU351, firmware version compatibility with existing application programs is verified prior to shipment. Customers requiring specific firmware revisions for validated control systems (pharmaceutical, nuclear auxiliary, SIL-rated applications) should specify the required revision at time of inquiry.

DriveKNMS provides cross-reference support for customers migrating from discontinued variants to functional equivalents within the Series 90-30 family, and documents known incompatibilities between hardware revisions to prevent field installation errors.

Quality Control for the Series 90-30 Range

Series 90-30 modules present specific test challenges due to their backplane bus architecture, battery-backed SRAM, and multi-layer PCB construction. DriveKNMS applies the following test protocol to all Series 90-30 units prior to dispatch:

• Backplane bus integrity test: Each module is seated in a Series 90-30 test rack and verified for correct bus arbitration, slot addressing, and data transfer at rated clock speed.
• CPU functional verification: CPU modules execute a standardized ladder logic test program covering timer, counter, math, and communications function blocks. Program execution time is measured against factory specification.
• Battery and SRAM check: Battery voltage is measured and replaced if below threshold. SRAM retention is verified over a 24-hour powered-off soak test.
• I/O channel-level test: Discrete modules are tested point-by-point for correct switching, leakage current, and response time. Analog modules are calibrated against a traceable reference standard and verified across the full input/output range.
• Communications module loopback test: Ethernet and serial modules are tested for correct frame transmission, error detection, and protocol handshake using protocol-specific test equipment.
• Visual and mechanical inspection: PCB surfaces, connector pins, and front-panel indicators are inspected for corrosion, mechanical damage, and counterfeit indicators.