Description
The GE Fanuc IC687RCM711B (Catalog Number: IC687RCM711-B) is a Redundancy Control Module (often designated as the RCM) designed for legacy GE Fanuc Series Six and Series 90-70 programmable logic controller (PLC) systems. Installed within a VME-based industrial rack architecture, the RCM coordinates dual-CPU fault-tolerant hot-standby configurations to ensure high availability and uninterrupted process control in critical industrial applications.
Key Specifications & Identification
| Attribute | Details |
| Manufacturer | GE Fanuc / GE Intelligent Platforms |
| Product Line | Series 90-70 PLC / VME Industrial Systems |
| Model / Part Number | IC687RCM711B (IC687RCM711-B) |
| Module Type | Redundancy Control Module (RCM) |
| System Architecture | Hot-standby dual-system CPU redundancy coordination |
| Backplane Interface | VMEbus interface standard for Series 90-70 racks |
| Communication Links | High-speed fiber-optic or copper inter-rack redundancy link ports for health checking and memory synchronization |
Primary System Functions
- Hot-Standby CPU Synchronization: Continuously mirrors program state, memory registers, and I/O status between a primary (active) PLC rack and a secondary (backup) PLC rack to allow seamless bumpless transfer during a fault.
- Health & Status Monitoring: Performs real-time watchdog and diagnostic handshakes across the redundant communication link, detecting processor faults, power supply failures, or communication degradations.
- Master Switchover Control: Automatically initiates a switchover of control authority to the backup rack if the primary CPU fails or goes offline, minimizing downtime in continuous industrial processes.
- VME Bus Management: Coordinates system bus transactions and ensures synchronized execution timing across redundant VME racks.
Servicing & Installation Guidelines
- Rack Power Isolation: Always de-energize the PLC rack and follow strict lockout/tagout (LOTO) procedures before inserting or removing the IC687RCM711B module to avoid VME bus lockups or backplane damage.
- ESD & Handling Precautions: Highly sensitive CMOS integrated circuits and microprocessors on the board require strict static control. Always wear a grounded anti-static wrist strap during handling.
- Firmware & Revision Compatibility: In a redundant pair, both the primary and backup racks must use matching hardware revision levels (e.g., matching “-B” suffixes) and identical redundancy link cabling to ensure reliable state-memory synchronization.
