Metso IOP Series Modules IOP365 Isolated Analog Input

Technical Dossier

Product Details And Specifications

Metso IOP Series Technical Notes

The Metso IOP (I/O Processor) series is a core I/O subsystem deployed within Metso's DNA (Distributed Control System) automation platform. Installed across heavy-process industries — including petrochemical refineries, pulp and paper mills, nuclear power stations, and offshore oil & gas platforms — the IOP series provides the field-level signal conditioning and isolation layer between field instruments and the DNA controller network. Its modular architecture allows hot-swap replacement without process interruption, a critical requirement in continuous-operation facilities. The IOP365, specifically, is an isolated analog input module designed for high-accuracy 4–20 mA and voltage signal acquisition with galvanic channel isolation, making it the preferred choice in environments with high ground-loop interference or intrinsically safe zone requirements.

The Evolution of IOP Series Architecture

The Metso IOP series was introduced as part of the Neles Controls / Valmet Automation DNA platform in the early 2000s, succeeding the older Damatic XD and Damatic Classic I/O architectures. Early IOP modules communicated over a proprietary backplane bus using time-division multiplexing. Mid-generation revisions introduced enhanced diagnostics, HART pass-through capability on analog channels, and improved EMC shielding to meet IEC 61000-4 standards. Later variants added redundancy support at the module level, allowing paired modules to operate in active-standby configuration without external switching hardware.

As Metso and Valmet separated their automation businesses (Valmet DNA vs. Metso DNA), the IOP hardware base remained largely shared through the transition period, with firmware divergence occurring post-2015. Many IOP modules are now in the mature-to-end-of-life phase of their product lifecycle. Metso has issued end-of-manufacturing notices for several variants, making third-party spare parts sourcing the primary long-term maintenance strategy for installed base operators. Compatibility between IOP generations is governed by the DNA system's I/O bus protocol version; cross-generation substitution requires firmware verification before deployment.

IOP Series Full Catalog & Functionalities (SKU List)

Analog Input (AI) Modules

• IOP365: 8-channel isolated analog input, 4–20 mA / 0–10 V, galvanic channel isolation, HART-capable
• IOP360: 8-channel non-isolated analog input, 4–20 mA, standard process signal acquisition
• IOP361: 8-channel analog input with high-resolution 16-bit ADC, for precision measurement loops
• IOP362: 4-channel isolated analog input, thermocouple / RTD input, temperature measurement module
• IOP363: 8-channel analog input, HART multiplexer-integrated, for asset management integration
• IOP364: 4-channel isolated mV input module, for low-level signal sources including load cells

Analog Output (AO) Modules

• IOP370: 8-channel analog output, 4–20 mA, for control valve and positioner drive signals
• IOP371: 4-channel isolated analog output, 4–20 mA, HART-capable, for critical control loops
• IOP372: 8-channel analog output with loop diagnostics, open-loop and short-circuit detection

Digital Input (DI) Modules

• IOP310: 32-channel digital input, 24 VDC, for discrete field device status acquisition
• IOP311: 16-channel digital input, 110/220 VAC, for high-voltage field signal interfacing
• IOP312: 32-channel digital input with SOE (Sequence of Events) timestamping, 1 ms resolution
• IOP313: 16-channel isolated digital input, 24 VDC, for intrinsically safe zone applications

Digital Output (DO) Modules

• IOP320: 16-channel digital output, 24 VDC, 0.5 A per channel, for solenoid and relay drive
• IOP321: 8-channel relay output, SPDT contacts, 230 VAC / 5 A, for high-power switching
• IOP322: 16-channel digital output with diagnostics, open-load and short-circuit detection per channel

Communication & Power Modules

• IOP100: I/O bus coupler / communication adapter, connects IOP rack to DNA controller network
• IOP101: Redundant I/O bus coupler, active-standby pair for high-availability configurations
• IOP200: 24 VDC rack power supply module, 10 A output, for IOP backplane power distribution
• IOP201: Redundant power supply module, hot-swap capable, for continuous-operation installations

Sourcing Hard-to-Find & Obsolete IOP Series Parts

For operators running Metso DNA systems with IOP-based I/O racks, DriveKNMS provides: (1) direct replacement units for discontinued SKUs, (2) cross-reference analysis to identify compatible substitute modules where direct replacements are unavailable, and (3) long-term supply agreements for facilities requiring guaranteed availability over multi-year maintenance contracts. All sourced units are subject to full functional verification before dispatch.

Quality Control for the IOP Series Range

IOP modules present specific test challenges due to their backplane-dependent communication architecture. Standalone bench testing is insufficient to verify bus communication integrity; DriveKNMS uses a dedicated Metso DNA I/O rack test bench that replicates the live backplane environment, allowing full functional verification of the I/O bus coupler interface, channel-level signal accuracy, isolation barrier integrity, and HART communication pass-through.