Valmet A413084 CPU Board – High‑Performance Processor Module

The Valmet A413084 is a powerful central processing unit board designed for the Valmet DNA distributed control system. Available in two main revisions – Rev 05 and the variant with part number 65422544A (often labeled CPU32 16M) – this module serves as the main computational engine for medium to large automation applications. It combines a 32‑bit RISC processor with generous memory and comprehensive communication interfaces to execute complex control strategies with deterministic response.

Processor and Memory Architecture

At the core of the A413084 is a 32‑bit CPU running at 66 MHz, featuring a hardware floating‑point unit and a memory management unit. The board is equipped with 16 MB of DRAM (hence the “16M” designation) and 4 MB of flash memory for firmware storage. An additional 512 KB of SRAM is used for high‑speed cache and critical data buffers. The 65422544A version includes an upgraded memory controller that supports faster access times, improving overall system throughput.

Communication Interfaces

The CPU board provides multiple communication channels: two 10/100Base‑T Ethernet ports for redundant network connectivity, one RS‑232 serial port for local maintenance, one RS‑485 port for Modbus or Profibus integration, and a CAN‑bus interface for I/O expansion. The Ethernet ports support PROFINET, Modbus TCP, and Valmet’s proprietary protocol, ensuring seamless integration with operator stations, engineering tools, and third‑party devices.

I/O and Peripheral Support

Although the A413084 does not have on‑board field I/O, it can control up to 128 remote I/O racks through the backplane or fieldbus. It includes a built‑in real‑time clock with battery backup, a hardware watchdog timer, and a temperature sensor for internal monitoring. The board also features a 4‑channel PWM output for simple actuator control and a 2‑channel frequency input for speed measurement.

Redundancy and High Availability

The module supports hot‑standby redundancy when paired with an identical unit. A dedicated synchronization link ensures seamless failover with a switchover time of less than 100 ms. The 65422544A revision improves the failover logic and adds a heartbeat monitoring feature. Both versions are designed for 24/7 operation in critical processes.

Software and Programming

The A413084 runs the Valmet real‑time operating system and executes applications built with the Valmet Engineering Tool, supporting IEC 61131‑3 languages (ladder, function block, structured text, sequential function chart). It also supports C/C++ routines for advanced algorithms. The board has a built‑in web server for remote diagnostics and can store up to 100,000 historical events in its internal flash.

Physical and Electrical Specifications

The board is a 6U Eurocard (233 mm x 160 mm) with a 96‑pin DIN connector for backplane attachment. It requires a +5 V DC supply at 1.5 A and a +24 V DC supply at 0.2 A. Power consumption is approximately 10 W. The front panel includes a graphical LCD display showing system status, IP address, and fault codes, along with four push‑buttons for local operation.

Environmental Conditions

Operating temperature range is ‑20 °C to +60 °C; storage from ‑40 °C to +85 °C. Humidity tolerance is 5‑95 % non‑condensing. The module is coated with a conformal layer for protection against dust and moisture. It meets CE, UL, and CSA safety standards, and is tested for vibration and shock per MIL‑STD‑810.

Installation and Commissioning

Insert the CPU board into the designated slot in the subrack, ensuring that the ejector handle is properly engaged. Connect the network cables and power wiring according to the system layout. Use the engineering tool to load the application program, set the IP addresses, and configure the redundant pair if used. Perform a power‑up self‑test; the LCD will show progress and any errors.

Applications

The A413084 is widely used as the primary controller for paper machine sectional drives, boiler combustion control, chemical batch reactors, and wastewater treatment plants. Its balanced performance and memory make it suitable for both continuous and sequential control applications.

Maintenance and Support

Routine maintenance includes checking the battery voltage (replace every 5 years) and cleaning the cooling vents. Firmware updates are available through the Valmet service portal and can be applied over Ethernet. The board logs all critical events; in case of failure, the LCD provides diagnostic codes. Spare units should be programmed identically for quick replacement.

Conclusion

The Valmet A413084 CPU board (Rev 05 and 65422544A) offers a robust, scalable processing platform for demanding automation tasks. Its combination of processing power, memory, and redundancy features ensures reliable and efficient control in critical industrial environments.