Metso IOP Series Modules IOP331

Technical Dossier

Product Details And Specifications

Metso IOP Series Technical Notes

The Evolution of IOP Series Architecture

The IOP series originated in the Neles Controls ND800 platform (circa 1992–1996), where first-generation IOP modules operated on a proprietary parallel backplane bus at 5 V TTL logic levels. These early units — including the IOP100 and IOP200 sub-families — used discrete ASIC-based I/O scanning with no onboard diagnostics beyond channel-level fault flags.

With the transition to Metso DNA (post-1999 Neles–Valmet merger), the IOP300 sub-family introduced a 32-bit embedded processor, HART pass-through on analog channels, and dual-redundant backplane arbitration. The IOP330 and IOP331 represent the mature expression of this architecture: full HART 5/6/7 support, 16-channel density, configurable input filtering, and compatibility with both ACN and ACSN (redundant) controller nodes.

IOP Series Full Catalog & Functionalities (SKU List)

Analog Input Modules

• IOP331: 16-ch analog input, 4–20 mA / HART 5/6/7, 16-bit resolution, dual-redundant backplane
• IOP332: 8-ch analog input, high-speed scan (10 ms), thermocouple/RTD configurable per channel
• IOP333: 16-ch analog input, HART 7 only, intrinsically safe barrier-compatible, ATEX Zone 1
• IOP334: 8-ch mV/thermocouple input, cold-junction compensation onboard, ±100 mV range

Analog Output Modules

• IOP341: 8-ch analog output, 4–20 mA sourcing, HART 5/6/7, 12-bit DAC, loop-powered diagnostics
• IOP342: 4-ch analog output, high-current 0–20 mA, valve positioner optimized, HART pass-through

Digital Input Modules

• IOP311: 32-ch digital input, 24 VDC, configurable debounce 1–100 ms, SOE 1 ms timestamp
• IOP312: 16-ch digital input, 120 VAC wet contact, optical isolation 2500 V, group commons
• IOP313: 32-ch digital input, NAMUR sensor compatible, short-circuit and wire-break detection
• IOP314: 16-ch digital input, 48 VDC, intrinsically safe, Zener barrier interface

Digital Output Modules

• IOP321: 16-ch digital output, 24 VDC sourcing, 0.5 A per channel, electronic fusing, diagnostics
• IOP322: 8-ch relay output, SPDT, 5 A / 250 VAC, mechanical and solid-state relay options
• IOP323: 32-ch digital output, 24 VDC sinking, 0.1 A per channel, high-density terminal base

Controller / CPU Modules

• IOP361: ACN application controller node, 133 MHz RISC, 64 MB SDRAM, dual Ethernet, IEC 61131-3
• IOP362: ACSN redundant controller pair interface, hot-standby switchover <50 ms, bumpless transfer

Communication & Specialty Modules

• IOP351: PROFIBUS DP master/slave, 12 Mbit/s, up to 125 slave nodes, GSD file management
• IOP352: Modbus RTU/TCP gateway module, 4 serial ports, configurable baud 1200–115200
• IOP353: Foundation Fieldbus H1 linking device, 2-segment, 32 devices per segment, LAS capable

Quality Control for the IOP Series Range

IOP series modules use a proprietary dual-bus backplane (primary + redundant) operating at 10 Mbit/s. Standard bench testing is insufficient to validate backplane arbitration behavior. DriveKNMS applies the following protocol for all IOP series units: