Description
GE Fanuc IC695CRU320-BB | PACSystems RX3i Redundancy CPU
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | GE Fanuc |
| Product Family | PACSystems RX3i |
| Catalog Number | IC695CRU320-BB |
| Product Type | Redundancy CPU |
| CPU Function | Hot Standby redundancy |
| Hardware Revision | BB |
| Associated Firmware Revision | 6.00 |
| User Memory | Up to 64 MB battery-backed RAM |
| Nonvolatile Flash | 64 MB |
| Embedded Serial Interfaces | RS-232, RS-485 |
| Serial Protocols | Modbus RTU Slave, SNP, Serial I/O |
| Backplane | RX3i PCI and high-speed serial bus |
| Program Blocks | Up to 512 |
| Maximum Block Size | 128 KB |
| Maximum Transfer List | Up to 2 MB |
| Redundancy Links | Up to two IC695RMX128/228 synchronization links |
| Floating Point | Yes |
| Operating Temperature | 0 to 60°C |
| Time-of-Day Clock | Maximum 2 seconds/day drift |
| Elapsed-Time Clock | 0.01% maximum accuracy |
| Power Requirement | +3.3 VDC, 1.0 A nominal; +5 VDC, 1.2 A nominal |
| ECC | Single-bit correction / multiple-bit checking |
| Redundancy Switchover | Maximum 1 logic scan; minimum specified 3.133 ms |
The published CRU320 specification identifies dual RX3i backplane-bus support, up to two redundancy synchronization links, 64 MB flash, and the RS-232/RS-485 serial interfaces.
Important Revision Detail
IC695CRU320-BB is not simply a cosmetic suffix. GE’s product information identifies the -BB hardware with firmware revision 6.00, released in May 2010. The release introduced functions including User Defined Types, Variable Indexed Arrays, Logic Driven Write to Flash, and Backplane Operations Controller enhancements.
Later CRU320 revisions introduced additional firmware and hardware changes. For example, the -BC revision corresponded to firmware 6.01, while -CD introduced the low-battery detection capability with firmware 6.02. This makes the exact hardware revision relevant when replacing an older controller in an established RX3i application.
Product Introduction
The GE Fanuc IC695CRU320-BB is a PACSystems RX3i redundancy CPU designed for controller architectures where continued machine or process operation depends on a standby CPU being able to assume control. It supports RX3i PCI and high-speed serial backplane buses and can use up to two IC695RMX128/228 redundancy synchronization links.
The practical procurement issue is the BB hardware revision. A CRU320 from a different revision should not be accepted solely because the catalog family matches. Firmware level, redundancy configuration, battery arrangement, application program, and synchronization hardware all need to be checked before putting a replacement into service.
IC695CRU320-BB
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
A CRU320 replacement is more complicated than replacing an ordinary RX3i CPU. In a redundant system, the controller has to maintain synchronization and transfer control correctly during a CPU switchover. A unit that powers up but has the wrong hardware or firmware revision can still create commissioning problems.
Typical Applications
- PACSystems RX3i hot-standby control systems
- Process-control applications requiring CPU redundancy
- Continuous production machinery
- Industrial PLC systems using IC695RMX redundancy synchronization modules
Technical Pitfalls to Avoid
- Match the complete hardware revision, not only “CRU320.”
IC695CRU320-BB is specifically associated with firmware 6.00. Later revisions introduced functional and hardware changes, so verify the existing CPU suffix before approving a replacement. - Check the redundancy synchronization hardware.
The CRU320 supports up to two IC695RMX128/228 synchronization links. The replacement CPU must be compatible with the redundancy architecture actually installed in the rack. - Do not confuse the CPU with the redundancy module.
The is the controller CPU. The IC695RMX128/228 provides the synchronization link between redundant controllers. Replacing one does not replace the other. - Check application and firmware compatibility before commissioning.
A replacement CPU may require the application to be reviewed in the programming environment rather than simply transferring the existing program. This is particularly important when replacing a -BB unit with a later hardware revision.
Related Products
- GE Fanuc IC695CRU320 — Base PACSystems RX3i redundancy CPU family designation.
- GE Fanuc IC695RMX128 — RX3i redundancy synchronization module used for CPU-to-CPU synchronization.
- GE Fanuc IC695RMX228 — Higher-capacity redundancy synchronization module option for architectures.
- GE Fanuc IC695CPE320 — RX3i CPU from the same general controller family; functionally different because it is not the redundancy CPU.
- GE Fanuc IC695PSA350 — RX3i power supply used to provide rack power for compatible systems.
- GE Fanuc IC695CHS007 — RX3i universal backplane option for controller and I/O assemblies.
- GE Fanuc IC695ETM001 — Ethernet interface module for RX3i systems where Ethernet connectivity is required.
- GE Fanuc IC695ACC302 — RX3i CPU lithium smart battery associated with battery-backed memory applications; battery condition should be checked during replacement.
Procurement Check
Before purchasing an IC695CRU320-BB, verify:
- Exact catalog number:
- Hardware revision: BB
- Existing firmware revision
- Redundancy architecture
- IC695RMX128 or IC695RMX228 synchronization hardware
- RX3i backplane configuration
- Application program and Proficy Machine Edition compatibility
- Battery condition and memory-retention requirements
- Existing serial-port configuration
- CPU configuration and redundancy parameters
- Firmware requirements for the installed I/O and communications modules
- CPU label and revision marking before shipment
Recommended procurement description:
GE Fanuc PACSystems RX3i Redundancy CPU, Hot Standby Controller, BB Hardware Revision, 64 MB Flash, RS-232/RS-485 Serial Interfaces, Compatible with RX3i Redundancy Synchronization Architecture.
The key distinction is simple: is the redundant CPU itself, not an RX3i I/O module or redundancy synchronization module. The -BB revision matters, and its documented firmware association is 6.00, so replacement decisions should be based on the complete CPU revision and installed redundancy architecture rather than the family name alone.
