Description
Technical Specifications
| Parameter | Details |
|---|---|
| Product Model | D201471 |
| Module Designation | DOI4RO |
| Manufacturer | Metso / Valmet Automation |
| Product Family | ACN I/O, M120 Series |
| Product Type | Relay digital output unit |
| Output Channels | 4 |
| Relay Contact Type | Potential-free, normally open (NO) |
| Output Voltage | Determined by external field supply |
| Maximum Resistive Load | 5 A at 120 VAC, 240 VAC, 24 VDC, or 48 VDC |
| Maximum Resistive Load at 125 VDC | 0.3 A |
| Maximum Inductive Load | 5 A at 120 VAC; 3 A at 240 VAC or 24 VDC |
| Maximum Switching Voltage | 260 VAC / 125 VDC |
| Output Update Interval | 1 ms |
| Configurable Safe-State Delay | 1 second to 4 hours |
| Safe-State Configuration | No change, 0, or 1 |
| Channel-to-Channel Isolation | 2200 VAC / 60 seconds |
| Channel-to-System Isolation | 1500 VAC / 60 seconds |
| Field Power Supply | Potential-free; external load supply required |
| Dimensions | 95 × 24 × 95 mm |
| Weight | Approximately 130 g |
These values are documented in the Metso ACN I/O M120 technical manual, section DOI4RO. The resistive and inductive load ratings are different and must not be treated as interchangeable.
Product Introduction
Metso D201471 DOI4RO Relay Output Module
The Metso D201471 is a four-channel relay digital output unit in the ACN I/O M120 family. Designated DOI4RO, it uses normally open, potential-free electromechanical contacts to switch external field loads. Typical applications include indicator lights, solenoid valves, and supplementary relays controlling motors or larger actuators.
Each channel provides electrical separation between the control system and its field circuit. The module also supports configurable output safe-state behavior, allowing the system to define whether an output remains unchanged or transitions to a specified state after a configured delay. This makes the D201471 relevant to legacy process-control installations where relay-based field switching is required.
D201471
Application Scenarios & Field Pitfalls
The D201471 is designed for process-control systems that need electrically isolated relay contacts rather than transistor-based DC outputs. Its potential-free contacts allow compatible AC or DC field circuits to be switched using an external power source. This is useful in older distributed I/O architectures where field devices operate at different voltage levels.
Potential application areas
- Switching solenoid valves in process-control installations.
- Operating indicator lamps and alarm circuits.
- Controlling motor contactors through supplementary relays.
- Discrete valve and equipment interlock circuits in industrial plants.
Engineer checks before replacement
- Verify the relay contact rating. The 5 A rating applies to specified resistive loads. Inductive loads have lower permitted current ratings, particularly at 240 VAC and 24 VDC.
- Check external field power. The relay contacts are potential-free. The module does not independently provide the voltage required by the connected field loads.
- Inspect the safe-state configuration. Confirm the configured delay and channel behavior. An incorrect safe-state setting can cause unintended actuator or relay operation following a controller fault.
- Check isolation requirements. The documented isolation ratings are 2200 VAC between channels and 1500 VAC between channels and the system, each for 60 seconds. Maintain the specified field wiring separation.
- Protect relay contacts. Use suitable suppression for inductive loads to limit switching transients and contact wear. Confirm the suppression method is appropriate for the AC or DC circuit.
- Verify the I/O connection hardware. The M120 installation documentation identifies dedicated cables and IXR8 cross-connection boards for the DOI4RO. Confirm the installed cable and terminal arrangement before replacement.
Related Products
The following components belong to the Metso ACN I/O M120 architecture or its associated control system. They serve different functions and are not direct substitutes for D201471.
- D201468 – DII4U125: Four-channel digital input module for 125 VDC field signals. Used for discrete status acquisition rather than relay output switching.
- D201469 – DII4U120: Four-channel digital input module for 120 VAC applications. Its input function differs from the output function.
- D201470 – DII4U240: Four-channel digital input module for 240 VAC signals. Relevant to the same M120 I/O architecture but not a replacement output card.
- D201466 – DII8P24: Eight-channel digital input module for 24 VDC signals. Suitable for discrete field-state acquisition.
- D201467 – DII8P48: Eight-channel digital input module for 48 VDC signals. Check the field voltage and connection arrangement before selection.
- D201472 – AII8CN: Eight-channel analog current input module for process measurement. It handles analog acquisition rather than relay switching.
- D201650 – IXR8: Cross-connection board used with the DOI4RO and other four-channel I/O modules. It is an installation accessory, not an I/O module.
- D201925 – ACN CS Node: Controller and gateway platform associated with the wider Metso ACN control architecture. It performs a different role from the field output module.
Procurement recommendation: Specify Metso / and confirm the hardware revision, front-panel designation, and connector condition. Ask for a functional relay test report covering all four channels. Do not accept a generic DOI4 transistor-output description as proof of equivalence: the documented uses normally open electromechanical relay contacts
