METSO DPU-MR high-performance Distributed Processing Unit

the Metso DPU-MR is a high-performance Distributed Processing Unit (the “Master” controller) specifically designed for the Metso DNA (formerly Valmet DNA) automation system.

It acts as the brain of the control system, executing complex logic and managing communication between I/O modules and the operator station.

1. Introduction

The DPU-MR is an advanced version of the standard Distributed Processing Unit, where “MR” typically denotes Master/Redundant capability.

It is responsible for executing real-time control applications, such as PID loops, interlocking, and sequence control.

It sits at the top of the I/O rack, collecting data from input modules (like the IOP series), processing that data, and sending commands to output modules to control the plant.

2. Technical Parameter Table

3. Related Models

The DPU-MR is the evolution of earlier processing units and often works alongside:

DPU4E / DPU4P: Earlier or standard versions of the Distributed Processing Unit.

ACN RT / ACN CS: More modern “Automation Cloud Node” controllers that have succeeded the classic DPU series in newer Valmet DNA systems.

IOP302 / IOP320: The I/O modules that are directly managed by the DPU-MR.

NIU (Network Interface Unit): Used to bridge DPU communication across different network segments.

4. Application Cases

Large-Scale Power Plants: Controlling turbine sequences and boiler fuel-to-air ratios where a controller failure is not an option.

Pulp & Paper Mills: Managing the complex, continuous logic of paper machines and fiber lines.

District Heating: Coordinating distributed heat exchangers across a city-wide network.

Critical Safety Interlocks: Used in burner management systems (BMS) where redundant processing is required for safety.

5. Product Advantages and Features

Seamless Redundancy: The DPU-MR is designed to work in pairs. If the primary unit fails, the “MR” standby unit takes over control bumplessly (in less than one processing cycle).

Deterministic Processing: Ensures that control logic is executed at exact, predictable intervals, which is critical for high-speed mechanical control.

Flash-Based Storage: Control applications are stored in non-volatile flash memory, meaning the system can reboot and resume control instantly after a power loss.

Advanced Diagnostics: Constantly monitors the health of the entire I/O subsystem, reporting specific card or channel failures to the operator before they cause a shutdown.

DPU-MR

6. Other Models in the Same Series

Within the Metso/Valmet DNA controller hierarchy, you will find:

DPU-SR: A “Single” version of the processor for non-critical applications.

ACN MR: The modern high-capacity controller for current Valmet DNA installations.

ACN F2: A compact controller used for small-scale or remote applications.

DPU-BC: Bus Controller units used specifically to manage communication traffic on the I/O backplane.