Metso IOP341 Positioner Module
The Metso IOP341 is a specialized Positioner Module (also known as a Turbine Valve Positioner) within the maxPAC I/O family, used in the Metso DNA and maxDNA Distributed Control Systems. It is specifically designed for the high-precision control of industrial valves and turbine actuators.
1. Introduction
The IOP341 is a dedicated interface for valve position control. Unlike standard analog output modules, the IOP341 is an intelligent “closed-loop” positioner.
It receives a position setpoint from the controller, reads the actual position from a feedback sensor (like an LVDT or potentiometer), and adjusts its output to the actuator until the setpoint is reached. This localized control loop offloads high-speed processing from the main DPU, ensuring extremely fast and stable valve regulation.
2. Technical Parameter Table
| Parameter | Specification |
| Model Number | IOP341 (Part No: 181560) |
| Module Type | Turbine Valve Positioner Module |
| Input Feedback | LVDT (Linear Variable Differential Transformer) or Potentiometer |
| Output Type | 4–20 mA or specialized actuator drive current |
| A/D & D/A Resolution | 16-bit high-precision conversion |
| Control Mode | PID-based closed-loop position control |
| Isolation | Channel-to-Logic Galvanic Isolation |
| Status Indicators | LEDs for Power, Run, and Loop Fault |
| Mounting | maxPAC I/O Chassis / IOT300-series base |
3. Related Models
The IOP341 is often paired with other high-performance turbine control modules:
IOP345: Pulse Input/Counter Module (used for speed/RPM sensing).
IOP342: A variant positioner module, sometimes used for different actuator impedances.
IOT341: The specific Terminal Base or Connection Pole used to land the sensitive LVDT wiring.
DPU-MR: The Master Redundant processor that sends setpoints to the IOP341.
4. Application Cases
Steam Turbine Control: Precisely modulating the main steam inlet valves (Governor/Stop valves) to maintain frequency or load.
Gas Turbine Actuators: Managing fuel valve positioning for combustion control.
Hydraulic Actuator Control: Interfacing with servo-valves that require fast, deterministic positioning in power plants.
Feedwater Regulating Valves: High-precision control of boiler water levels in utility-scale power generation.
| DEIF | PPU-3 |
| DELL | X1052P |
| DELL | X1052 |
| DELTA TAU | CLIPPER INTERFACE BOARD 603926-101 |
| DELTA TAU | USBEDCH2SE1GB P/N:DEUH2-01G17I72AC1SB-B235 |
| DELTA TAU | ACC-24E2A |
| DELTA TAU | POWER PMAC UMAC 465CPU |
| DIGIFAS | DIGIFAS7105 |
| DIGIFAS | DIGIFAS7108 |
| DIGIFAS | DIGIFAS7116 |
| DMS | VME-PROF-S |
| DOBOTECH | DQM CARD REL.1.0 0310071 |
| DOBOTECH | DQM CARD REL.1.0 0310072 |
5. Product Advantages and Features
Localized Processing: By managing the PID loop directly on the card, the module provides a response time faster than the standard system scan cycle.
LVDT Support: Specifically optimized for LVDT sensors, which are the industry standard for rugged, high-vibration valve feedback.
Fail-Safe Logic: Features configurable fail-states; if communication with the DPU is lost, the module can be set to “Hold,” “Open,” or “Close” the valve automatically.
High Accuracy: 16-bit resolution ensures that even minute adjustments in valve position are executed, minimizing process oscillation and fuel waste.
6. Other Models in the Same Series
The IOP341 is part of the maxPAC / Metso DNA high-performance controller lineage:
IOP302: 16-channel Analog Input (4-20mA).
IOP320: 8-channel Analog Output (4-20mA).
IOP331: 16-channel 48V Digital Input.
PDP601: High-speed Distributed Processing Unit.