METSO IOT300A Terminal substrate / Interface module
The Metso IOT300A is a specialized Terminal Base / Interface Module designed for the Metso DNA and maxDNA Distributed Control Systems.
It acts as the physical mounting and wiring foundation for the IOP series (Input/Output Processing) modules.
1. Introduction
The IOT300A is part of the maxPAC I/O subsystem. Unlike the “IOP” modules which contain the active electronics and logic, the IOT300A is a passive or semi-passive base unit.
It provides the mechanical slot for the I/O modules to plug into and features the terminal connections for field wiring.
It is engineered to ensure that field signals are cleanly routed to the processing electronics while allowing for easy module replacement.
2. Technical Parameter Table
| Parameter | Specification |
| Model Number | IOT300A (Part No: 181630) |
| Component Type | Terminal Base / I/O Base Unit |
| Module Compatibility | Compatible with IOP302, IOP320, IOP331, etc. |
| Mounting | Standard maxPAC Rack / DIN Rail Assembly |
| Wiring Method | Screw-type or Tension-clamp terminals |
| Connection Density | Typically supports 16 to 32 field wire points |
| Backplane Interface | Integrated bus connector for DPU communication |
| Operating Temp | 0°C to +60°C |
| Material | Industrial-grade, flame-retardant polymer |
3. Related Models
The IOT300A is the foundation for the “plug-in” modules previously discussed:
IOP302: Analog Input Module (plugs into IOT bases).
IOP331: Digital Input Module (plugs into IOT bases).
IOT300B/C: Variants with different terminal layouts or earthing (grounding) configurations.
CPO Series: Connection Pole components that sometimes sit atop or alongside the IOT base for specialized wiring.
IOT300A
4. Application Cases
Control Room Cabinets: Centralized termination of hundreds of field cables in power plants or refineries.
Remote I/O Stations: Used in distributed boxes closer to the process machinery to reduce wiring costs.
System Retrofits: Often used when upgrading older Bailey or Westinghouse systems to Metso DNA, providing a structured wiring interface.
| CLIPPARD | R311 |
| CMZ | SVM1608/SER.000 |
| COEN ISCAN | DSF-2000-UV DSF-2000-MB-UV 2653-213-06 |
| Cognex | 800-5715-1 REV D |
| COGNEX | 800-5745-1 |
| COGNEX | 800-5746-1 |
| COGNEX | MVS-8100C |
| COMAIR ROTRON | FE12B3 |
| COMIZOA | COMI-LX504 |
| COMPACTPCI | DM/V2400A-CPCI |
| COMPLEE | CP48 450V |
| COMPRESSOR CONTROLS CORP | MCP-1004 |
| CONCURRENT | SSI232.1 029.365.083 |
| CONCURRENT | VP32502X |
| CONTEC | ACO/DCO-8(98) |
| CONTEMPORARY | MODHUB-16E |
5. Product Advantages and Features
Hot-Swap Support: The IOT300A allows active IOP modules to be removed and replaced while the system is powered, as the field wiring remains permanently attached to the IOT base.
Robust Connectivity: Designed to handle vibration and thermal expansion, ensuring that field connections do not loosen over years of industrial operation.
Clear Labeling: Features dedicated space for channel identification, reducing the risk of wiring errors during installation or maintenance.
Simplified Troubleshooting: Provides easy-access test points for technicians to measure field signals directly at the terminal without disconnecting wires.
IOT300A
6. Other Models in the Same Series
The IOT300A is part of the maxPAC / Metso DNA Hardware infrastructure:
DPU4E: Distributed Processing Unit (connects to I/O via the IOT backplane).
IOT305: Specialized base for high-voltage digital signals.
IOT308: Base unit designed for redundant I/O configurations.
PSM303: Power Supply Module that distributes power through the IOT base bus.