METSO PDP601 high-performance Distributed Processing Unit
The Metso PDP601 is a high-performance Distributed Processing Unit (DPU), essentially the “central controller” or CPU module for the Metso DNA and maxDNA automation systems.
It is engineered to handle complex logic, data processing, and communication across large-scale industrial networks.
1. Introduction
The PDP601 (Part Number 181585) is the core intelligence of a control rack.
It collects data from input modules (IOP series), executes the programmed control strategies (PID loops, interlocks, sequences), and sends commands to the output modules.
As a “Distributed” unit, it operates autonomously but coordinates with other processors over a high-speed network to manage an entire plant’s operation.
2. Technical Parameter Table
| Parameter | Specification |
| Model Number | PDP601 (P/N: 181585) |
| Processor | 32-bit RISC CPU (PowerPC-based) |
| Memory (RAM) | 128 MB SDRAM (Application memory) |
| Storage (Flash) | 64 MB (OS and Firmware storage) |
| Network Interface | 2x Ethernet (10/100 Mbps) for DNA Network |
| Serial Ports | 1x RS-485 (Modbus RTU support) |
| Redundancy | 1:1 Hot Standby (Failover < 50 ms) |
| Scan Cycle | Configurable down to 10 ms |
| Isolation | 1500 V AC |
| Operating Temp | -25°C to +70°C (Extended industrial range) |
3. Related Models
The PDP601 is part of the high-tier controller lineup and is frequently associated with:
PDP406: An earlier version of the Distributed Processing Unit.
DPU-MR: The Master Redundant processor used in similar maxDNA architectures.
ACN C20 / ACN RT: Modern “Automation Cloud Nodes” that serve as the current generation of Valmet controllers.
IOP302 / IOP320: The analog input/output cards controlled by the PDP601.
PDP601
4. Application Cases
Process Automation: Managing continuous production lines in pulp, paper, and chemical plants.
Power Plant Control: Coordinating boiler and turbine logic where high-speed processing and redundancy are vital.
Mining & Metals: Used in crushing, grinding, and flotation circuits to process large volumes of sensor data.
Distributed HVAC/Utilities: Controlling district heating and cooling networks across multiple remote sites.
5. Product Advantages and Features
High Fault Tolerance: Supports 1:1 redundancy. If the primary processor fails, the secondary unit takes over in less than 50ms without bumping the process.
Deterministic Execution: Guarantees that control tasks are executed at precise intervals, which is essential for stable PID control and safety interlocks.
Robust Hardware: Unlike standard PLCs, the PDP601 is built for extreme temperature ranges (-25°C to +70°C), allowing it to be mounted in field cabinets without specialized cooling.
Scalability: Capable of managing up to 16.000 I/O points and over 50.000 function blocks, making it suitable for both small machines and massive plant sections.
| DEIF | SCM-1 |
| DEIF | IOM4.2 |
| DEIF | PCM4.3 |
| DEIF | SCM4.1 |
| DEIF | TAC-311DG |
| DEIF | PCM4.4 |
| DEIF | LSU-112DG |
| DEIF | DU-2/MKIII |
| DEIF | DLQ144-PC-NB |
| DEIF | DELOMATIC-3 DGU2 |
| DEIF | PSM-1 |
| DEIF | CM-2 |
| DEIF | IPM-1 |
| DEIF | OPM-1 |
| DEIF | RMV-112D |
6. Other Models in the Same Series
The PDP series consists of several variations depending on the system age and complexity:
PDP601 Revision E4/E7: Common hardware revisions found in the field.
PDP406 / PDP402: Legacy processors still found in older Metso/Valmet installations.
ACN (Automation Cloud Node): The “successor” series to the PDP, used in the most recent Valmet DNA versions.