IC695CMU310: Max-On Hot Standby Redundancy in an RX3i CPU
The IC695CMU310 is an RX3i CPU with Max-On hot standby redundancy, and the name describes the behaviour precisely: both CPUs run the same application at the same time, and one takes over when the other fails. There is no switchover delay to budget because there is no switchover — the standby is already executing.
That architecture is the point. A warm-standby arrangement has to detect the failure, promote the backup and resync state before the process can be trusted again, and that sequence takes time. With both CPUs running, the failure response is bounded by how quickly the surviving CPU detects the loss and assumes control, not by how long it takes to bring an idle processor up to speed.
| Feature | Specification |
|---|---|
| Manufacturer | GE Fanuc / GE Intelligent Platforms |
| Brand | GE |
| Part Number | IC695CMU310 |
| Brand | GE Fanuc | Series: RX3i PacSystem | Part Number: IC695CMU310 | Product Description: Max-On Hot-Standby Redundancy CPU | Number of Slots: Single Slot | Power Requirements: 1 Amp at +5 Volts DC, 1.25 Amps at +3.3 Volts DC | Communication Ports: RS-232, RS-485 | Protocol Support: Modbus RTU Slave, SNP, Serial I/O | Backplane: Dual backplane | Program Storage: 10 Mbytes of RAM and User Memory | Operating Temperature: 0 to 60 degrees Celsius | Floating Point: Yes | Weight: 1 Pound |
RX3i CPU and Redundancy Options
CPU selection on RX3i is driven by capacity, scan performance and the redundancy scheme required. Confirming the redundancy requirement before ordering matters because a CPU without hot standby capability cannot be made redundant by pairing it with another CPU of the same type:
| RX3i Part Number | CPU / Redundancy Function |
|---|---|
| IC695CPE302 | RX3i processing module — confirm capacity and redundancy scheme against the system design |
| IC695CPE305 | RX3i processing module — confirm capacity and redundancy scheme against the system design |
| IC695CPE310 | RX3i processing module — confirm capacity and redundancy scheme against the system design |
| IC695CPE330 | RX3i processing module — confirm capacity and redundancy scheme against the system design |
| IC695CPE400 | RX3i processing module — confirm capacity and redundancy scheme against the system design |
| IC695CRU320 | RX3i processing module — confirm capacity and redundancy scheme against the system design |
All GE parts · CPU Modules · PLC & I/O Modules
What Max-On Changes in Commissioning
With both CPUs executing the application, commissioning has a step that a single-CPU system does not: verifying that the two CPUs agree. A pair that diverges will produce output from both, which on a machine with interlocks or safety-relevant outputs is a worse condition than either CPU being down.
- Confirm both CPUs are running the identical application version.
- Verify the pair reports as synchronised before the process is placed in automatic.
- Test the failover deliberately, under controlled conditions, rather than waiting for a real failure.
- Confirm output modules are driven by the active CPU only, per the system design.
Deliberate failover testing is the step most often skipped and the one that reveals configuration errors while there is still time to fix them.
Failure Response and Sizing
The standby arrangement does not change the I/O base the system needs — the same input and output modules serve either CPU. It changes the CPU slot count and the rack power budget, since two CPUs draw power and both must be supported. On racks approaching the power supply limit, that budget has to be recalculated with both CPUs running, because a +5 V rail sized for one CPU is not sized for two.
Supply & terms: Stock status: In Stock · Condition: New · Warranty: One Year · Origin: US. Listed by AutoDCS Tech Parts Team · Last updated .
Availability & Condition at AutoDCSTech
| Part Number | IC695CMU310 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
