Key Technical Specifications

• Product Model: IC697CHS770
• Manufacturer: GE Fanuc / Emerson
• System Compatibility: GE Series 90-70 PLC System
• Chassis Type: Dual Redundant Rear Mount Rack
• Redundancy: Full Dual Redundant Backplane Architecture
• Input Voltage: 120V AC/DC (Typical for this series)
• Module Compatibility: Series 90-70 I/O, CPU, and Comm Modules
• Environmental Rating: Industrial Grade, Designed for Harsh Environments
• Mounting Style: Rear Mount (Back-of-panel installation)
• Warranty: 12 Months

 

Product Introduction

When a refinery or power plant can’t afford a single second of downtime, the backplane is the unsung hero keeping the plant alive, and the IC697CHS770 is exactly what keeps dual-redundant Series 90-70 systems breathing. I’ve wired up dozens of these rear-mount racks in cramped, dusty control cabinets, and they are built like tanks to handle the physical stress of industrial environments. It is a dedicated dual redundant chassis that provides the physical housing and the critical parallel backplane bus required to run two CPUs and their associated I/O in perfect, synchronized lockstep.Maintenance teams choose this specific GE rack because true hardware redundancy is a non-negotiable safety requirement for critical infrastructure. The dual redundant backplane design ensures that if the primary CPU or its backplane traces fail, the secondary system takes over instantly without dropping a single scan. I’ll give you one piece of advice from the field: these rear-mount racks are heavy and awkward to wrestle into a panel, but once bolted down and properly grounded, they are absolutely bulletproof.

Quality SOP & Tech Pitfalls

• The Lab Report (SOP): We don’t just wipe the dust off and ship it. Every IC697CHS770 goes through a strict protocol: visual counterfeit check, live test on a Series 90-70 test rack to verify backplane continuity, insulation resistance checks with a Fluke 115, hardware revision logging, and finally, anti-static sealing.
• The Engineer’s Warning (Pitfalls): The biggest mistake I see guys make is ignoring the grounding strap on the rear mount. I once watched a technician spend an entire weekend chasing ghost communication faults and random CPU resets, only to realize he had mounted the rack on painted sheet metal without scraping the paint off for the ground lug. The backplane had no earth reference, and ESD was frying his modules. Always scrape the paint. Always.

 

Installation & Configuration Guide

1. Pre-Installation: ⚠️ SAFETY FIRST. Lock out and tag out all power to the control panel. Wait at least 5 minutes for internal capacitors to discharge. Take a high-resolution photo of the old chassis, specifically focusing on all ground wire terminations, jumper settings, and module slot assignments.
2. Removal: Label every single wire before disconnecting. Remove the mounting nuts/bolts securing the rear-mount chassis to the panel. Do not yank the chassis; these old metal frames can bend if forced against the panel cutout.
3. Installation: CRITICAL STEP: Scrape the paint or coating off the panel where the chassis ground lug sits. This prevents 90% of backplane noise issues. Seat the new IC697CHS770 firmly against the panel and torque the mounting hardware to spec.
4. Power-On & Testing: Re-energize the 120V AC/DC input. Verify the power supply LEDs illuminate correctly. Check the primary and secondary CPU diagnostics to ensure both processors are recognizing the redundant backplane and entering RUN mode without bus faults.

Compatible Replacement Models

• ✅ Drop-in Replacement: GE IC697CHS771. 100% hardware and software match. The 771 is typically the direct successor or alternate revision; it will function identically in the dual redundant configuration.
• ⚠️ Software Compatible: GE IC697CHS782 / 783. Same physical footprint and Series 90-70 compatibility, but requires verifying firmware compatibility with your specific redundant CPUs. Expect 1-2 hours of engineering time to recompile and download logic if a firmware handshake fails.
• ❌ Hardware Mod Required: GE IC698CRE016 (PACSystems RX3i). Requires completely rewiring, new I/O modules, and new chassis backplane modifications. Explicitly advise against using this unless you are doing a full system migration away from the obsolete Series 90-70 platform.

 

Frequently Asked Questions (FAQ)

• Can I hot-swap modules in this redundant rack safely?
  No. While the Series 90-70 supports hot-swapping of some I/O modules, the chassis itself and the CPUs are not hot-swappable. Pulling a CPU or power supply while energized can arc the backplane connectors and fry the redundant bus. Kill the power first.
• Is the IC697CHS770 a direct replacement for the IC697CHS750?
  No. The 750 is a standard (non-redundant) rear mount rack. If you put a 750 in a system designed for dual redundancy, your secondary CPU will never sync, and you will lose your safety architecture. You must use a 770 or 771.
• I installed it, but the secondary CPU is showing a rack fault. What gives?
  9 times out of 10, it’s a grounding issue or a seating problem. Did you scrape the paint for the ground lug? If yes, pull the CPUs and reseat them. The Series 90-70 backplane pins can get slightly bent over decades of use, preventing the redundant bus from making contact.
• Are these brand new or refurbished?
  We deal in New Surplus and original OEM stock. Because this is an obsolete GE Fanuc part, true “factory sealed” units are rare. We guarantee 100% original equipment, fully tested on a live Series 90-70 rack, and backed by a 1-year warranty.
• Will this work with standard Series 90-70 I/O modules?
  Yes. The IC697CHS770 is the backbone for the entire 90-70 ecosystem. It accepts standard 90-70 CPUs, I/O, and communication modules, but it provides the extra redundant bus traces required for high-availability setups.