GE IC698RMX016-ED Redundant Memory Xchange (Reflective Memory) Module

Description

In high-availability industrial automation and process control systems, ensuring ultra-low-latency synchronization between redundant CPUs or across multiple controllers is critical to preventing data divergence, switchover delays, or loss of deterministic behavior during faults. Traditional Ethernet-based redundancy can introduce variable latency, packet loss risks, or CPU overhead, while older parallel links limit distance and speed—issues that become prohibitive in expansive or mission-critical setups where even milliseconds of mismatch could compromise safety, production continuity, or regulatory compliance.

The GE IC698RMX016-ED directly overcomes these limitations as a 16 MB Redundant Memory Xchange (RMX) module in the PACSystems RX7i platform, providing a dedicated fiber-optic reflective memory link for real-time data mirroring. It proves essential when implementing hot-standby CPU redundancy or multi-node reflective memory networks, such as synchronizing primary and backup controllers in fault-tolerant architectures. Engineers regularly specify the GE IC698RMX016-ED for applications demanding high reliability, sub-microsecond data propagation, and zero CPU processing burden in industrial automation. Its reflective memory technology automatically replicates writes across all nodes without software intervention, supporting seamless bumpless failover and shared data access in process control environments.

By delivering deterministic, high-speed memory sharing over fiber, this module enables objectives like minimized recovery time, robust fault isolation, and scalable high-availability designs without the complexities of networked protocols.

The GE IC698RMX016-ED operates as a reflective memory node within the RX7i VME architecture, installed in the main rack to create a dedicated high-speed link—typically paired between redundant CPUs or in ring topologies with multiple controllers. It mirrors data changes instantaneously: any write to local memory is broadcast over the fiber-optic network, updating remote nodes in real time without involving the host CPU or requiring protocol stacks.

Connected via LC-type fiber connectors, it supports point-to-point redundancy links or multi-node rings, with dynamic packet sizing for optimal throughput. The module handles network error detection, programmable interrupts, and parity checks independently, while diagnostics appear through status LEDs and Proficy Machine Edition software. Configuration parameters—like node ID, redundant transfer mode, and memory offsets—are set via the RX7i CPU hardware config, with no DIP switches needed.

In redundancy mode, it partners with CPUs like the CRE series for automatic synchronization; in general reflective mode, it enables shared memory across distributed controllers. Positioned this way in the automation stack, the GE IC698RMX016-ED offloads synchronization entirely to hardware, preserving CPU cycles for logic execution and ensuring consistent performance across local VME I/O and remote nodes.

Implementing the GE IC698RMX016-ED equips RX7i systems with hardware-level synchronization engineered for uncompromising availability, where ultra-fast memory replication directly safeguards process integrity during faults.

Its independent operation ensures long-term performance by eliminating software-induced delays or failures, resulting in reliable switchovers and reduced risk of data inconsistencies. Maintenance becomes more efficient, as built-in error detection and LED status allow rapid identification of fiber or node issues without deep diagnostics.

Integration stands out—the GE IC698RMX016-ED reduces engineering overhead through software-only configuration and hot-swap capability, fitting seamlessly into existing VME racks while supporting fiber runs for physical separation of redundant units. This hardware autonomy preserves deterministic scan times even under heavy logic loads.

The real-world value centers on peace-of-mind redundancy: instantaneous mirroring that supports stringent uptime demands, allowing focus on application logic rather than managing synchronization vulnerabilities.

The GE IC698RMX016-ED is commonly found in power generation facilities, where it synchronizes redundant CPUs for turbine or grid control, providing critical system uptime amid electrical noise and extended distances.

In oil and gas or chemical processing, it enables reflective memory networks for distributed safety systems, ensuring deterministic data sharing in harsh conditions with vibration and temperature extremes. Water/wastewater plants often deploy it in hot-standby setups for pump and valve coordination across large sites, supporting fast failover and process control continuity.

These use cases emphasize tolerance for fiber-based separation and zero-latency replication in power plants or infrastructure applications.

GE IC698CMX016 – Control Memory Xchange variant for non-redundancy reflective applications

GE IC698CRE020 – Compatible 700 MHz redundancy CPU requiring RMX for hot standby

GE IC698CRE030 – Higher-speed redundancy CPU partner for intensive synchronization

GE IC698CRE040 – Top-performance redundancy CPU with expanded capabilities

GE IC698CPE020 – Non-redundant CPU counterpart for standard high-availability builds

GE IC698ETM001 – Ethernet module to complement RMX networking

GE IC698PSA100 – Power supply commonly paired in redundancy racks

Before deploying the GE IC698RMX016-ED, confirm CPU firmware (version 2.00 or later) and Proficy Machine Edition compatibility for configuration download. Verify main rack power supply capacity handles the 1.8 A draw alongside other modules, and plan slot placement—ideally 3 or 4 for interrupt priority.

Use multimode fiber with LC connectors, keeping runs within specifications (typically up to 300 m per segment), and ensure clean terminations to minimize insertion loss. Power off the rack during insertion for safety.

Maintenance involves periodic LED checks for network status and errors, annual fiber connector cleaning/inspection in dusty environments, and occasional link health verification via software diagnostics. Hot-swap support allows replacement without system shutdown.