What Is the IC695NIU001?
The IC695NIU001 is a PACSystems RX3i Ethernet Network Interface Unit (ENIU) from GE Intelligent Platforms/GE Fanuc, now manufactured by Emerson Automation. It acts as the communication bridge between RX3i CPUs and legacy Series 90-30 I/O modules over Ethernet. If your plant runs mixed RX3i and Series 90-30 hardware, this module keeps data exchange automatic after configuration.
This unit fits a single slot and supports a dual backplane bus: RX3i PCI and 90-30-style serial. Two serial ports (RS-232 and RS-485) handle Modbus RTU Slave, SNP, Serial I/O, and Modbus RTU Master via application “C” block. Built-in 10 MB flash memory stores user data, and firmware upgrades happen in-system.
Key Technical Specifications
| Specification | Value |
|---|---|
| Power at +3.3 VDC | 1.25 Amps nominal |
| Power at +5 VDC | 1.0 Amps nominal |
| Internal power at 5 VDC | 0.95 A |
| Internal power at 3.3 VDC | 0.52 A |
| Backplane support | Dual: RX3i PCI and 90-30-style serial |
| Communication ports | RS-232, RS-485 |
| Integrated memory | 10 MB flash |
| Optional local logic | 20 KB |
| PCI compatibility | PCI 2.2 standard |
| Redundant controller configuration | Supported |
| Floating point | Yes |
| Battery | IC695ACC302 (recommended), IC693ACC302, or IC698ACC701 |
These specs matter for real deployments. The dual backplane support means you can mix RX3i and Series 90-30 modules in one station without extra adapters. The 10 MB flash and 20 KB local logic give you room for data storage and small control routines. Redundant controller support adds a layer of reliability for critical processes.
Where the IC695NIU001 Fits
Legacy I/O Migration
Many plants still run Series 90-30 I/O but want RX3i control. The IC695NIU001 lets you keep existing 90-30 racks while upgrading the CPU side. You avoid a full rip-and-replace, which cuts downtime and capital cost.
Remote I/O Stations
Because the module communicates over Ethernet, you can place I/O racks away from the main control room. It exchanges Ethernet Global Data (EGD) with master devices, and the controller monitors status in every exchange. This suits large facilities where cable runs would be expensive.
Redundant Control
With redundant controller configuration supported, the module works in setups where uptime is critical. If one controller fails, the system can switch without losing I/O communication.
Installation and Setup
The IC695NIU001 installs in a single slot of an RX3i universal backplane. You need a complete NIU station: backplane, power supply, at least one RX3i Ethernet module (IC695ETM001), and this NIU. Configure it with Machine Edition Logic Developer software, version 5.51 or later. The module uses a battery-backed clock; replace the battery with IC695ACC302, IC693ACC302, or IC698ACC701 when needed. Follow GE/Emerson wiring and grounding instructions exactly.
Compatibility and Integration
The module supports SNP, Modbus RTU Slave, Serial I/O, and Modbus RTU Master (via “C” block). It works with RX3i PacSystems CPUs and Series 90-30 I/O. Ethernet communication goes through the backplane-installed Ethernet Interface Module (IC695ETM001). It also supports SRTP for IP/TCP services. For a complete assembly, order the NIU kit IC695NTK001 or IC695NTK002.
Maintenance and Reliability
Inspect the module periodically for loose connections and dust buildup. The battery is the main wear item; check its status and replace it with the recommended part numbers. Keep the operating environment within the rated range. For safety-related systems, follow the manufacturer’s safety manual and never attempt internal repairs.
Buyer’s Checklist
Before you buy, confirm your backplane type, CPU model, and whether you need redundant control. Verify that you have the required Ethernet module and correct software version. Check battery part numbers and consider a spare. Since lifecycle status may change, please verify current lifecycle status and availability with SpareTechPLC before ordering. SpareTechPLC stocks industrial automation parts and can help you match the right NIU kit for your station.
Frequently Asked Questions
Q: What is the difference between the IC695NIU001 and a standard RX3i CPU?
A: The IC695NIU001 is a network interface unit, not a CPU. It enables RX3i CPUs to communicate with Series 90-30 I/O over Ethernet. It does not run the main control program.
Q: Can I use the IC695NIU001 with a Series 90-30 backplane?
A: Yes. The module supports dual backplane bus: RX3i PCI and 90-30-style serial. This lets you mix RX3i and Series 90-30 modules in one station.
Q: What software do I need to configure the IC695NIU001?
A: You need Machine Edition Logic Developer software, version 5.51 or later. Configuration sets up data exchange, which then runs automatically.
Q: How do I replace the battery in the IC695NIU001?
A: Use RX3i CPU Lithium Smart Battery IC695ACC302 (recommended), Series 90-30 Lithium Battery Pack IC693ACC302, or IC698ACC701 Smart Coin Cell Battery Pack. Follow the manual for safe replacement.
Q: Does the IC695NIU001 support redundant controllers?
A: Yes, redundant controller configuration is supported. This helps maintain communication if one controller fails.
