Metso IOP320 is an Analog Output Module
The Metso IOP320 is an Analog Output Module belonging to the maxPAC I/O family within the Metso DNA (formerly Valmet DNA) and maxDNA Distributed Control Systems.
While the IOP302 is designed to bring signals into the system, the IOP320 is responsible for sending precise control signals out to field devices like control valves and actuators.
1. Introduction
The IOP320 is an 8-channel analog output module that converts digital commands from the Distributed Processing Unit (DPU) into standard 4–20 mA analog signals.
It is engineered for high-availability environments (such as power generation and large-scale processing) where precise valve positioning and reliable signal transmission are critical to plant safety and efficiency.
2. Technical Parameter Table
| Parameter | Specification |
| Model Number | IOP320 (Part No: 181545 / 69230I320A) |
| Output Channels | 8 Channels |
| Output Signal Range | 4–20 mA (Standard) |
| Loop Power | 24V DC (Individually fused per channel) |
| Scanning Mode | Scanned by DPU (typically ~20-100 msec) |
| Isolation | Field-to-Logic Galvanic Isolation |
| Resolution | High-resolution DAC (Digital-to-Analog Converter) |
| Power Supply | 24V system supply via backplane edge connector |
| Operating Temp | 0°C to +55°C |
| Dimensions | 15.8 cm x 3.2 cm x 5.5 cm |
3. Related Models
The IOP320 often works alongside other signal-specific output modules in the same rack:
IOP321: Isolated 4–20 mA Output Module (provides higher isolation between channels).
IOP322: Isolated Analog Output Module (often used for voltage signals or specialized ranges).
IOP302: The analog input counterpart (16 channels).
IOP350/351: Relay output modules for discrete (On/Off) control.
4. Application Cases
Control Valve Actuation: Modulating the position of steam or water valves in power plant boilers.
Variable Speed Drives (VSD): Sending speed setpoints to industrial motor controllers.
Chemical Dosing: Precise control of pump speeds in pulp and paper chemical stages.
Damper Control: Adjusting airflow in large-scale HVAC or combustion systems.
| BERGHOF | CEDIO-S |
| BERGHOF | RTEMP8/16 |
| BERGHOF | CDIO 16/16-0,5-1131 |
| BERGHOF | QAIO16/4-V |
| BERTHOLD | LB 440-M |
| BETA LASERMIKE | DB 25 PSU |
| BIOPTICS INC | 2010-00005 |
| BOARD T11312 | NAS-497E F3N3K0057-C3 |
| BOMBARDIER | DTCC742A |
| BOSCH | SE110 0608830109 |
| BOSCH | SF-A4.0125.015-14.057 |
| BOSCH | SM50/100-T |
| BOSCH | LTE12 0.6KVA |
| BOSCH | DCIO-2/MK-UL |
5. Product Advantages and Features
Individual Channel Protection: Each of the 8 channels is individually fused. This prevents a single field wiring short-circuit from taking down the entire module.
Diagnostic Feedback: Features dual LED indicators:
Active LED: Indicates the module is powered and communicating with the DPU.
Fuse Status LED: Specifically monitors the status of the loop power fuses for immediate troubleshooting.
Configurable “Fail-Safe” States: Supports jumpers (like W2) to determine if the output should Hold its last value or Reset to zero upon a communication failure.
Hot-Swappable: Can be replaced while the system is live, significantly reducing maintenance downtime.
6. Other Models in the Same Series
The IOP320 is a core component of the maxPAC / Metso DNA hardware line:
DPU4E / DPU404: The controllers that command the IOP320.
IOP303: 8-channel RTD input module.
IOP330/331: 16-channel digital input modules (24V/48V).
CPO309: Connection options for redundant I/O configurations.