GE IC695NIU001 Ethernet Network Interface Unit (ENIU)

Description

Why Your System Needs the GE IC695NIU001

In large-scale industrial automation systems, especially those spanning wide geographical areas or utilizing legacy I/O equipment, centralized control becomes increasingly complex and costly. Running dedicated field wiring back to a central Programmable Logic Controller (PLC) for every single input and output point is inefficient and sacrifices system modularity. The challenge for engineers is to efficiently integrate remote, high-density I/O clusters—potentially including older Series 90-30 modules—with a modern, high-performance control platform like the GE PACSystems RX3i. This integration must be fast, reliable, and provide comprehensive diagnostics across the network.

The core problem the GE IC695NIU001 (Ethernet Network Interface Unit) solves is providing a sophisticated, dual-protocol communication gateway that allows a PACSystems RX3i backplane to function as a remote I/O station over a standard Ethernet network. This module is essential for applications requiring distributed I/O architecture. It eliminates the need for a full-scale local CPU in the remote rack, instead allowing the RX3i’s power, speed, and advanced I/O (including high-speed analog or discrete modules) to be deployed exactly where they are needed—closer to the field devices. This ability to bridge the high-speed RX3i PCI backplane to the ubiquitous Ethernet network is the cornerstone of flexible, cost-effective process control system design, ensuring high reliability for remote I/O signal exchange.

How the Product Works & Fits into a System

The GE IC695NIU001 is the intelligence unit of a remote I/O rack. It is an Ethernet Network Interface Unit (ENIU) that plugs into an RX3i backplane, effectively turning that backplane into a communications slave or remote I/O node. It utilizes an external Ethernet Interface Module (typically the IC695ETM001) that is also installed in the rack to physically connect to the network. The IC695NIU001 manages all data traffic between the remote I/O modules on the rack’s backplane (which supports both the modern RX3i PCI bus and the legacy 90-30 Serial bus) and the master controller over the Ethernet link.

Once configured via the central control platform software (Proficy Machine Edition), the module automatically handles the critical task of real-time data exchange, primarily using Ethernet Global Data (EGD). EGD is a high-speed, peer-to-peer protocol that enables fast, predictable updates of I/O data between the NIU and the main controller. System control is provided by a master device capable of exchanging EGD, which could be an RX3i CPU or another controller on the network.The NIU ensures that the controller receives not just I/O status, but also comprehensive diagnostics about the NIU and the health of the remote rack.

Adding to its versatility, the GE IC695NIU001 also features two embedded serial ports configurable for RS-232 and RS-485 communication.These ports support popular serial protocols like Modbus RTU Slave, SNP, and Modbus RTU Master via application ‘C’ blocks. This allows the remote rack to simultaneously communicate with local serial devices (like weigh scales or panel displays) and manage the core Ethernet I/O, providing a powerful, multi-protocol communication hub for industrial automation and minimizing the need for additional gateway devices.

Technical Highlights Summary

Real-World Benefits

The most significant benefit of the GE IC695NIU001 is the increased flexibility and scalability it brings to distributed industrial automation systems. By decoupling the I/O rack from the main controller via Ethernet, engineers can place I/O closer to the field devices, minimizing long wiring runs that are expensive and susceptible to noise. This module is engineered for communication resilience, allowing the RX3i platform’s performance capabilities to extend across large facilities or remote sites without the necessity of installing a costly, fully redundant CPU at every location.

The unique dual-backplane support is a high-value feature, ensuring long-term performance and providing a seamless upgrade path for legacy systems. This allows users to re-utilize existing, reliable Series 90-30 I/O modules in the remote rack alongside new, high-performance RX3i modules. This approach significantly protects prior investments and reduces engineering overhead by eliminating the need for a full, disruptive system re-wire and replacement of all field I/O.

Furthermore, the embedded serial ports and the 10 MB of built-in flash memory provide additional utility.The memory can be used for local data logging or recipe storage, reducing network traffic and reliance on the central controller for non-critical tasks.The comprehensive diagnostic features automatically monitor the status of the NIU and the I/O on its rack, providing the main controller with the precise health data needed for proactive maintenance and faster fault recovery, greatly enhancing overall system high reliability.

Typical Use Cases

The GE IC695NIU001 is the ideal solution for expanding control networks in challenging environments. A prime deployment is in large infrastructure projects, such as municipal water distribution or long-distance oil and gas pipelines. In these systems, remote booster pump stations or valve skids, which are geographically separated from the main control center, can utilize the IC695NIU001 to serve as a local I/O concentration point, communicating essential data over the site’s existing fiber optic or copper Ethernet backbone.

Another crucial application is in automotive manufacturing or material handling lines. When adding a new production cell, the module allows for rapid deployment of a new RX3i I/O rack without altering the central PLC program’s core structure. This modularity ensures fast commissioning and minimal disruption to the existing line, which is critical for maximizing production throughput.

The dual backplane capability is heavily leveraged in facilities undergoing phased modernization, such as legacy power plants. The GE IC695NIU001 allows the replacement of an aging PLC with a new RX3i CPU while retaining functional Series 90-30 I/O racks as remote nodes, ensuring critical system uptime throughout the upgrade process.

Compatible or Alternative Products

GE IC695ETM001 – The required Ethernet Interface Module that provides the physical Ethernet ports for the GE IC695NIU001 to connect to the network.

GE IC695NIU002 – A variant of the Network Interface Unit, sometimes offering enhanced features or compatibility with different system architectures.

GE IC695CPE310 – A typical high-performance RX3i CPU used as the master controller that communicates with the IC695NIU001 remote rack.

GE IC695CHS016 – A 16-slot universal backplane that the GE IC695NIU001 is designed to plug into.

GE IC695PSM300 – A power supply module necessary to provide operating power to the backplane and the IC695NIU001.

GE IC693CPU374 – An example of a high-end Series 90-30 CPU, which this module allows I/O from to be utilized in an RX3i architecture.

Setup Notes & Maintenance Insights

Before implementing the GE IC695NIU001, ensure the backplane power supply (IC695PSxxxx) can handle the combined power draw of the NIU, the associated ETM module, and all downstream I/O modules, paying attention to both $3.3\text{ VDC}$ and $5\text{ VDC}$ requirements. The NIU requires one physical slot but often uses the space of two slots (virtually), and it is typically recommended to install it in the lower-numbered slots of the backplane. Configuration within Proficy Machine Edition is mandatory to define the NIU’s role, its EGD data exchanges with the master controller, and the mapping of its serial ports.

Routine maintenance focuses on battery replacement and diagnostic checks. The internal battery (such as the recommended IC695ACC302) maintains the Real-Time Clock and RAM memory and has an estimated life of 5 years.It is critical to replace the battery on a scheduled basis, ensuring that the new battery is connected while the unit is powered on to prevent data loss or power-up issues. Monitoring the module’s status LEDs and the diagnostic tables reported in the master PLC’s program will quickly reveal any communication errors, EGD exchange problems, or hardware faults within the remote rack, facilitating a practical, proactive maintenance approach.