GE IC697CMM742: Keeping Legacy 90-70 Systems Talking on Ethernet

If you’re still running GE 90-70 PLCs in your plant (and let’s be honest, plenty of paper mills and municipal water facilities are), this little workhorse is why they haven’t completely fallen off the network. One thing I appreciate is how it slips right into aging chassis without demanding new power supplies or cabinet overhauls. You might notice it won’t win any speed contests—this isn’t gigabit territory—but for pulling HMI data or basic SCADA comms out of 1990s-era controllers? It typically gets the job done without breaking the bank.

Key Features That Keep Old Systems Alive

• Legacy 90-70 Backplane Compatibility – Plugs directly into IC697 chassis slots. No adapter needed, which saves real estate in cramped control panels. Saw a brewery retrofit last month where this avoided a $15k cabinet replacement.
• Dual 10Mbps Ethernet Ports – Lets you daisy-chain devices or create simple network segments. Not blazing fast, but perfectly adequate for Modbus TCP polling in most wastewater plants I’ve visited.
• No External Power Required – Draws juice straight from the backplane. One less PSU to fail in dusty environments (though you’ll want to check those aging capacitors periodically).
• Basic Diagnostics via LEDs – Link/activity lights on front panel. Simple, but when your midnight shift tech is troubleshooting, that blink pattern can save an hour of downtime.

Technical Specs at a Glance

Where You’ll Actually Use This

From my experience, it’s the go-to when factories can’t justify ripping out functional 90-70 systems. Think municipal water treatment plants needing to push flow data to new SCADA dashboards, or food processing lines where the original PLC still controls critical processes. One cement plant client told me: “It’s not pretty, but it’s kept our kiln controls online for 8 years after the OEM stopped supporting.” Exactly this kind of stopgap solution.

Why Procurement Teams Keep Ordering It

Let’s be real—you’re not buying this for cutting-edge performance. You’re buying it because replacing entire control systems costs 10x more than dropping this $400 module into existing hardware. The 365-day warranty gives peace of mind for legacy gear, and compatibility with standard 90-70 chassis means your maintenance crew won’t need retraining. And yes, it won’t handle modern protocols like Profinet, but for basic Ethernet/IP or Modbus? Typically does the job quietly for years.

Installation & Maintenance Reality Check

Mount it in any standard IC697 chassis slot—no special brackets. But here’s what manuals don’t emphasize: leave at least 20mm clearance above/below for airflow. I’ve seen too many fail from heat buildup in overpacked cabinets. Clean vents quarterly with compressed air (dusty environments clog them fast). Firmware’s fixed, so no updates needed, but check LED patterns during routine rounds—flashing red usually means cable issues, not module failure. One plant manager told me this saved his night shift $2k in emergency service calls last year.

Certifications & Peace of Mind

Carries UL 508 listing (critical for North American industrial use) and meets CE marking for EMC. RoHS compliant despite its age—GE got ahead of that curve. Warranty’s straightforward: 365 days from shipment date covering defects in materials/workmanship. No fine print about “legacy products excluded.” Delivery usually ships within a week if in stock, though older revisions might take up to 30 days. Payment’s 50% upfront with balance before shipping—FedEx/UPS/DHL options available. Honestly, for keeping decades-old systems limping along? Hard to beat the economics.