Fuji WPLAC-30 Retrofit-Compatible CPU for Legacy Systems

Fuji WPLAC-30 Retrofit-Compatible CPU for Legacy Systems

The Fuji Electric WPLAC-30 is a retrofit-compatible CPU module engineered for the MICREX-SX SPH Series programmable logic controller platform. As legacy Fuji MICREX-SX installations approach end-of-life and original spare parts become increasingly scarce, the WPLAC-30 provides a reliable, drop-in compatible solution for facilities seeking to extend the operational lifespan of their existing control infrastructure without committing to a full system overhaul.

Designed for industrial environments where uptime is critical, the WPLAC-30 supports seamless integration into existing MICREX-SX backplane architectures. It is compatible with the SPH series rack and I/O bus structure, allowing maintenance engineers to replace a failed or aging CPU without redesigning the control cabinet layout or rewriting the entire application program. This makes it an ideal choice for process plants, utilities, and discrete manufacturing facilities that rely on Fuji MICREX-SX platforms for continuous production control.

NINERMAS maintains verified stock of the WPLAC-30 and offers pre-shipment functional testing, ensuring that every unit dispatched meets operational specifications before it reaches your facility. All units are covered by a 12-month warranty from the date of delivery.

Upgrade Compatibility Table

Retrofit Planning for Existing Automation Systems

Replacing the WPLAC-30 in an active MICREX-SX installation requires a structured approach that accounts for the full scope of the control system architecture. Before initiating the swap, engineers should audit the existing rack configuration, documenting each installed module by slot position and address. In a typical SPH-series cabinet, the CPU slot is flanked by a combination of digital input modules, digital output modules, and analog I/O cards — all of which retain their configuration independently of the CPU and do not require replacement during a CPU-only retrofit.

Power supply capacity is a critical pre-check. The rack power supply — commonly a WPOW-10 or similar SPH-series power module — must have sufficient headroom to support the WPLAC-30 alongside all installed I/O modules. If the existing power supply is already operating near its rated output, a parallel power supply or a higher-capacity replacement should be considered before the CPU swap proceeds.

Communication continuity is another key concern. Many MICREX-SX installations interface with operator HMI panels via RS-232C serial links or Ethernet-based SCADA connections. The WPLAC-30’s communication port configuration must be verified against the existing wiring and protocol settings. If the legacy CPU used a dedicated WCOM-10 or similar communication module for Modbus RTU or PROFIBUS DP connectivity, those modules remain in place and their configuration is unaffected by the CPU replacement — provided the new CPU firmware supports the same communication driver versions.

For installations that include remote I/O expansion via a WRIO-10 or equivalent remote I/O master module, the WPLAC-30 must be configured to recognize the remote rack addresses during the hardware configuration download. This is performed using the Fuji SX-Programmer Expert or equivalent engineering tool, where the I/O map is verified and the program is re-downloaded to the new CPU. Engineers should retain a backup of the original program file and hardware configuration before beginning any work.

HMI screen tag references should also be audited. If the facility uses a Fuji UG Series or third-party HMI panel communicating with the MICREX-SX CPU, the tag database and communication driver settings must be confirmed to remain valid after the CPU swap. In most cases, tag addresses are preserved as long as the program structure and data register assignments are unchanged.

Signal isolation requirements should be reviewed for analog I/O channels. Where legacy wiring connects field transmitters directly to analog input modules such as the WANA-10, signal isolators may be in place to protect the module inputs. These isolators remain in service and do not require reconfiguration during a CPU-only replacement.

Finally, if the installation includes a WMEM-10 memory backup module or battery-backed RAM cartridge, the program retention strategy should be confirmed. The WPLAC-30 should be loaded with the verified program file from the engineering workstation rather than relying on a legacy memory cartridge of unknown condition.

Downtime Control During System Migration

Minimizing production downtime during a WPLAC-30 CPU replacement requires advance preparation and a disciplined execution sequence. The most effective approach is to complete all pre-work — program backup, hardware configuration export, HMI tag audit, and spare parts staging — before the maintenance window begins. This ensures that the physical swap and recommissioning can be completed within a single planned outage, typically achievable in two to four hours for a well-prepared team.

Before powering down the rack, the existing CPU’s program and hardware configuration should be uploaded and saved to the engineering workstation. This provides a verified fallback in the event that the replacement unit requires any configuration adjustment. The rack should then be powered down in the correct sequence — field devices first, then the control rack — to avoid spurious output signals during the transition.

Once the WPLAC-30 is installed in the correct rack slot, the hardware configuration is downloaded first, followed by the application program. I/O forcing should be used cautiously during initial power-up to verify that field signals are reading correctly before releasing the system to automatic control. Communication links to HMI panels and SCADA systems should be confirmed active before the system is handed back to operations.

Where a cold standby strategy is in place — with a pre-configured WPLAC-30 held in stock and loaded with the current program — switchover time can be reduced to under one hour. NINERMAS recommends maintaining at least one pre-tested spare CPU in the facility’s critical spares inventory to support this approach, particularly for continuous process applications where extended downtime carries significant production cost.

Retrofit Support FAQ

Q1: Is the WPLAC-30 a direct drop-in replacement for my existing MICREX-SX SPH CPU?
In most SPH-series installations, the WPLAC-30 is compatible with the existing rack, backplane, and I/O bus without mechanical modification. However, firmware version alignment and hardware configuration compatibility should be verified using the Fuji SX-Programmer tool before installation. NINERMAS can assist with compatibility confirmation based on your existing system documentation.

Q2: Does NINERMAS perform pre-shipment testing on the WPLAC-30?
Yes. Every WPLAC-30 unit dispatched by NINERMAS undergoes functional testing prior to shipment to confirm operational integrity. A 12-month warranty is provided from the date of delivery, covering manufacturing defects and functional failures under normal operating conditions.

Q3: What wiring or terminal changes are required when replacing the CPU?
The WPLAC-30 installs into the CPU slot of the SPH-series rack and does not require changes to field wiring or I/O terminal blocks. Communication cables connected to the CPU’s serial or Ethernet ports should be re-connected after installation and verified for correct protocol settings. No rewiring of I/O modules is required for a CPU-only replacement.

Q4: What is the lead time and stock availability for the WPLAC-30?
NINERMAS maintains stock of the WPLAC-30 and can confirm current availability upon inquiry. For facilities with planned maintenance schedules, we recommend confirming stock and placing orders in advance to ensure units are on-site before the maintenance window. Contact our team at sale@ninermas.com or +0086 187 5021 5667 for availability and lead time confirmation.