GE Fanuc Series Six 8717 Modules - 8717-CA-PS

Technical Dossier

Product Details And Specifications

GE Fanuc Series Six 8717 Series Technical Notes

The GE Fanuc Series Six 8717 platform is a rack-based programmable logic controller system deployed extensively across global heavy industry, including petrochemical refineries, nuclear power auxiliary systems, offshore platforms, and continuous-process chemical plants. Introduced in the early 1980s as part of GE's Series Six PLC architecture, the 8717 backplane and module ecosystem established a standard for modular, slot-addressable industrial control that remained in active production service well into the 2000s. Installed base counts in the tens of thousands of racks globally, making long-term spare parts availability a critical operational requirement for plant maintenance engineers and reliability teams.

The Evolution of 8717 Architecture

The Series Six 8717 architecture was built around a parallel backplane bus with dedicated slot addressing, supporting up to 12 I/O modules per rack in standard configurations. Early revisions (circa 1982–1988) used discrete TTL logic for bus arbitration; later revisions introduced ASIC-based bus controllers that improved noise immunity in high-EMI environments such as arc furnace control rooms and motor control centers. The CPU modules evolved from the 8717-CPU-100 (single-scan, fixed memory) through the 8717-CPU-300 series (expanded ladder logic capacity, floating-point support) to the 8717-CPU-501 (enhanced diagnostics, battery-backed SRAM). Communication adapters were added progressively to support GE's proprietary Genius Bus, then Modbus RTU, and finally Ethernet TCP/IP bridging via external gateways. The 8717 series reached end-of-production announcement by GE Fanuc in approximately 2008, with official end-of-support following in 2015. All modules are now classified as obsolete/legacy, placing the entire catalog in the long-term maintenance and lifecycle-extension category. Replacement migration paths lead to the GE Fanuc Series 90-30 (IC693 prefix) and Series 90-70 (IC697 prefix) platforms, though direct I/O mapping requires engineering re-configuration.

8717 Full Catalog & Functionalities (SKU List)

Power Supply Modules

• 8717-CA-PS: 120/240 VAC input, 5 VDC/8 A rack power supply for standard Series Six chassis
• 8717-CB-PS: 24 VDC input redundant power supply module for Series Six main rack
• 8717-CC-PS: High-capacity 5 VDC/15 A power supply for fully populated 12-slot racks

CPU / Controller Modules

• 8717-CPU-100: Base Series Six CPU, 4 KB ladder logic memory, fixed scan cycle
• 8717-CPU-200: Extended memory CPU, 8 KB program store, enhanced fault logging
• 8717-CPU-300: High-performance CPU with floating-point math and expanded I/O table
• 8717-CPU-501: Advanced CPU with battery-backed SRAM, online program change support

Digital Input (DI) Modules

• 8717-DI-115A: 16-channel 115 VAC discrete input module, optically isolated
• 8717-DI-24D: 32-channel 24 VDC discrete input, sink/source configurable
• 8717-DI-230A: 8-channel 230 VAC discrete input for high-voltage field devices

Digital Output (DO) Modules

• 8717-DO-115A: 16-channel 115 VAC triac output, 0.5 A per point
• 8717-DO-24D: 32-channel 24 VDC transistor output, sourcing type
• 8717-DO-RLY: 8-channel relay output module, Form C contacts, 2 A/point

Analog Input (AI) Modules

• 8717-AI-4: 4-channel analog input, 4–20 mA / 0–10 V selectable, 12-bit resolution
• 8717-AI-8: 8-channel analog input, differential or single-ended, 12-bit ADC

Analog Output (AO) Modules

• 8717-AO-4: 4-channel analog output, 4–20 mA, 12-bit DAC, loop-powered compatible

Communication / Adapter Modules

• 8717-CMM-001: Genius Bus interface adapter for Series Six rack, 153.6 kbps
• 8717-CMM-002: Modbus RTU master/slave communication module, RS-485

Quality Control for the 8717 Range

The 8717 backplane uses a parallel bus architecture with edge-connector gold contacts that are susceptible to oxidation and fretting corrosion after years of field service. DriveKNMS applies a standardized test protocol for all 8717 modules prior to dispatch. Power supply modules (including the 8717-CA-PS) are load-tested at 100% rated current for a minimum of 4 hours with output ripple measured against GE Fanuc specification limits (1500 VAC for AC input modules), leakage current, and response time. Communication modules are loopback-tested on live Genius Bus and Modbus RTU networks. All units that pass receive a DriveKNMS test certificate with date stamp and technician ID. Units that fail are quarantined and not returned to inventory.