Product Core Brief

• Brand: GE Fanuc / Emerson Automation
• Model: IC695NIU001
• Series: PACSystems RX3i
• Core Function: Ethernet Network Interface Unit (NIU), operating as remote slave station controller. Enables an entire RX3i rack (or mixed RX3i / Series 90‑30 I/O) to function as distributed remote I/O over Ethernet via EGD (Ethernet Global Data) communications with a central RX3i host CPU. Supports limited local standalone control logic and serial field device connectivity.
• Type: Single-slot universal backplane specialty processor module
• Condition: New Original (New Surplus)
• Status: ⚠️ Discontinued OEM production; limited surplus inventory
• Key Spec Highlights: Supports EGD remote I/O exchange, up to 20KB local control logic, dual serial ports (RS‑232 + RS‑485), battery-backed real-time clock, 10MB onboard flash, firmware upgradeable, works with IC695ETM001 Ethernet module for network access.

Key Technical Specifications

• Backplane Power Draw +3.3 VDC: 1.25 A nominal +5 VDC: 1.00 A nominal
• Local Logic Capacity: Max 20 KB program memory (all IEC languages except C blocks)
• Non-Volatile Storage: 10 MB onboard flash memory
• Clock: Battery-backed real-time clock (requires replaceable lithium battery)
• Serial Interfaces · COM1: RS‑232 D-Sub · COM2: Isolated RS‑485 D-Sub
• Supported Serial Protocols: SNP, Serial I/O, Modbus RTU Master / Modbus RTU Slave
• Network Mechanism: Communicates to host RX3i CPU via EGD (Ethernet Global Data)
• Ethernet Hardware Requirement: Must be paired with IC695ETM001 Ethernet module installed within the same RX3i rack
• Maximum Data Exchange: Up to 1300 bytes output from host; up to 1300 bytes input sent back to host
• Redundancy Support: Accepts outputs from dual redundant host RX3i CPUs for bumpless remote station control
• Supported I/O: Native RX3i IC695 series modules; compatible with Series 90‑30 I/O via expansion backplane
• Front Panel Status LEDs: NIU OK, Scanning I/O, Outputs Enabled, I/O Force, System Fault, COM1 Active, COM2 Active, Battery Status
• Configuration Software: Proficy Machine Edition (minimum v5.51)
• Firmware: Field upgradeable
• Operating Temperature: 0 °C ~ +60 °C
• Humidity: 5%–95% non‑condensing
• Hot Swap: Not officially supported; full rack power down recommended for module replacement
• Certifications: UL, CE

Product Introduction

Large distributed manufacturing and water treatment facilities deploy remote I/O racks separated from the main control room. GE turns an entire RX3i chassis into an Ethernet-connected remote I/O station. Instead of installing a full RX3i CPU at each field location, the NIU exchanges all input/output data with a central host PLC using EGD. It can execute small segments of local control logic to maintain basic operation during temporary Ethernet loss. Dual serial ports allow direct connection to Modbus instruments, HMIs or legacy serial devices on-site. Standard single-slot RX3i form factor allows direct drop-in spare replacement during planned maintenance outages.

Key Selling Points & Differentiators

1. GE enables cost-effective distributed remote I/O architecture without deploying full RX3i CPUs at every field rack.
2. Supports dual redundant host CPUs, allowing seamless switchover for high availability process control systems.
3. Embedded local logic capability maintains critical field operation if Ethernet communications to the main host are interrupted.
4. Every unit undergoes full bench validation on an RX3i test chassis; EGD data exchange, serial protocol operation, LED diagnostics verified prior to shipment. Signed test documentation available on formal request. Warranty runs 12 months post delivery.
5. Not compatible with RX7i, Series 90‑70 or Series 90‑30 main racks; designed exclusively for RX3i universal backplane architecture.
6. Integrated RS‑232/RS‑485 serial ports eliminate requirement for extra communications modules for local Modbus and SNP devices at remote stations.

Quality Transparency SOP

• Incoming Verification: Serial traceability validation, anti-counterfeit visual inspection, D-Sub serial port and battery socket hardware cross-check.
• Live Bench Test: Dedicated RX3i test rack, power-on self-test, EGD remote I/O simulation, Modbus serial master/slave testing, continuous 24-hour thermal soak cycling.
• Electrical Tests: 500 V megger insulation resistance testing, backplane power rail stability verification.
• Hardware Verification: Confirm LED array and serial communication circuits operate per datasheet; no unauthorized component rework performed.
• Final QC & Packaging: Anti-static shielding, shock-dampened transit carton, signed QC Pass label. Test images and logs available on request. No zero-failure performance guarantee.

Technical Risk Avoidance Section

Mandatory ETM Module Requirement Risk Risk: NIU cannot connect to Ethernet on its own. Missing or faulty IC695ETM001 results in complete loss of host communications. Prevention: Always verify presence and health of the rack Ethernet module. Field note: Multiple pumping station retrofits experienced remote rack offline after technicians replaced NIU001 but neglected to troubleshoot failed ETM001.

Battery Expiry Risk Risk: Aging lithium battery loses RTC and memory backup capability after extended power outages. Prevention: Schedule battery replacement concurrently with module exchange.

Local Logic vs Host Logic Conflict Risk Risk: Improper coordination between host control program and NIU local logic creates conflicting output commands. Prevention: Clearly define handoff logic for communications-fallback mode in project documentation.

ESD Damage Risk Risk: Unprotected handling damages serial transceivers and backplane interface circuits without immediate visible fault indicators. Prevention: Use grounded wrist straps; keep the module sealed inside anti-static packaging until rack insertion.

Critical Summary: Confirm rack layout and presence of IC695ETM001 before procurement. This module is a remote I/O slave station controller, not a CPU, and cannot be substituted with RX3i CPU modules without full system architecture redesign.

FAQ

1. Q: Can GE be installed into RX7i or Series 90‑70 racks? A: No. It is built exclusively for RX3i universal backplanes; mechanical and electrical interfaces are incompatible with other GE PLC families.
2. Q: Does work standalone without a host RX3i CPU? A: Limited functionality only. It can run small local logic, but full remote I/O operation requires a central host PLC exchanging data via EGD.
3. Q: Does this module support hot-swap replacement while the RX3i rack remains energized? A: Hot swap is not supported. Power down the remote chassis before removing or installing the module.
4. Q: What lead times apply for available inventory? A: In-stock units ship within 1–3 business days. Backordered allocations require 5–7 week lead times subject to global surplus availability.
5. Q: What failure modes fall outside warranty coverage? A: The 12-month limited warranty covers manufacturing defects. Damage from expired backup battery, ESD, improper serial wiring, and operation outside published temperature range is excluded.
6. Q: What is the difference between and an RX3i CPU like IC695CRU320? A: NIU001 is a remote I/O slave optimized for EGD data exchange; it relies on a host CPU for main control logic. RX3i CPUs are standalone master controllers capable of executing full application programs and hosting remote racks. They are not interchangeable.
7. Q: Can the serial ports run Modbus RTU master to field transmitters and valve controllers? A: Yes. The RS‑485 port supports Modbus RTU master mode for direct connection to field instrumentation at remote I/O racks.