The IC695CPE330 is the most capable backplane CPU in the PACSystems RX3i line — a 64MB, dual-core controller purpose-built for high-availability applications where both the CPU and the PROFINET I/O network must survive a hardware failure without process interruption. It is the only RX3i backplane CPU to combine Hot Standby CPU Redundancy with PROFINET System Redundancy (PNSR), delivering synchronized failover from the controller through to the I/O device level.

How does Hot Standby Redundancy work on the CPE330?

Two CPE330 CPUs operate in lockstep — one active, one standby. The standby CPU tracks the active CPU's program state, I/O data, and register values in real time. On failure detection, the standby assumes control within one scan, with PROFINET I/O devices seamlessly switching to the newly active controller via PNSR. No I/O re-enumeration, no communication loss to field devices. The embedded OPC UA Server supports Non-Transparent Server Redundancy — HMI and SCADA clients connect to a single virtual OPC UA endpoint that automatically routes to whichever CPU is active.

What I/O redundancy topologies are supported?

PROFINET System Redundancy supports both ring and star I/O topologies. In a ring configuration, MRP-capable PROFINET devices form a closed loop with dual paths to each controller — a single cable break only degrades to a linear topology without losing any I/O device. In a star topology with redundant PNC001 PROFINET Controllers, up to 20 redundant I/O devices can be served. Genius I/O redundancy (via IC695GCG001 gateway) and Ethernet Global Data (EGD) are also supported for legacy installations.

How does the CPE330 compare to the CPE400?

Both offer Hot Standby CPU Redundancy, but the architectures differ. The CPE330 mounts in a universal backplane (occupying 2 slots) and draws power from the rack — it lives in a traditional control cabinet with local I/O modules. The CPE400 is rackless, DC-powered, and connects to I/O exclusively over PROFINET — it is designed for distributed topologies without a central rack room. The CPE330 supports expansion racks, Genius I/O, and serial I/O modules that the CPE400 cannot accommodate. Choose the CPE330 for high-density centralized I/O with legacy module support; choose the CPE400 for distributed edge control with PACEdge analytics.

Frequently Asked Questions

Does the CPE330 have serial ports?

No. The CPE330 lacks onboard RS-232 and RS-485 ports — a notable difference from the CPE310. Serial communication (Modbus RTU, ASCII Serial) requires a rack-mounted serial communications module. This omission reflects the CPE330's role as an Ethernet-centric high-availability CPU.

What is the energy pack for?

The IC695ACC402 Energy Pack (included in the IC695CPK330 bundle) provides sufficient hold-up power to write the entire 64MB user memory to non-volatile storage on power loss. On restoration, the controller resumes from the saved state — critical for processes where a cold restart after a power outage is unacceptable.