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Phone: +86 16626708626Description
Key Technical Specifications
| Parameter | Specification / Value |
|---|---|
| Manufacturer | Metso Automation (Valmet / Neles) |
| Part Number | AO4H |
| System Compatibility | Metso DNA, maxDNA Distributed Control Systems (DCS) |
| Output Channels | 4 Analog Output Channels |
| Output Signal Range | 0/4 to 20 mA DC |
| Protocol Support | HART Protocol Pass-Through / Overlay on all 4 channels |
| Channel Isolation | Galvanically isolated channels |
| Accuracy / Resolution | 12-Bit to 16-Bit D/A Conversion (±0.1% full-scale accuracy) |
| Power Supply | Backplane bus powered via I/O baseplate (24 V DC loop supply) |
| Operating Temperature | 0 to +55 °C (+32 to +131 °F) |
| Mounting Format | Metso DNA I/O Sub-rack / Baseplate Slot Mount |
| Weight | Approx. 0.40 kg (0.88 lbs) |
Product Introduction & Supply Chain Strategy
The Metso AO4H is a heavy-duty 4-channel analog output module engineered for Metso DNA (now Valmet) distributed control systems. Supporting 4–20 mA current loops overlaid with digital HART communication protocols, the AO4H module drives control valve positioners, variable frequency drives, and process actuators while continuously passing smart field instrument diagnostic data back to the central engineering station.
Sourcing the Metso AO4H as New Surplus provides plant procurement teams and process automation engineers with a low-risk, rapid-replacement strategy. In continuous process industries like pulp & paper, chemical processing, and mining, an analog output card failure can cause control valve freezing, plant trips, or process contamination. Holding an unused original AO4H in safety stock bypasses OEM lead times and eliminates the failure risks associated with secondhand or repaired electronics, reducing Total Cost of Ownership (TCO).
AO4H
AO4H
Installation & Configuration Guide
1
Pre-Installation & Safety Isolation
De-energize node power and wear grounded ESD strap
1.Pre-Installation & Safety Isolation:De-energize node power and wear grounded ESD strap.
- Lock out and tag out auxiliary power to the target Metso DNA I/O baseplate slot.
- Put on an ESD grounded wrist strap connected to cabinet earth ground before handling the card.
- Document channel loop assignments and verify that external loop power sources are properly isolated.
2
Card Extraction & Slot Inspection
2.Card Extraction & Slot Inspection:
- Unlatch the retaining clips or faceplate locking screws on the existing AO4H module.
- Pull the ejector handles smoothly outward to disengage the rear connector from the baseplate backplane.
- Slide the board straight out along the guide rails, taking care not to twist or stress the backplane interface pins.
3
Hardware Alignment & Insertion
3.Hardware Alignment & Insertion:
- Inspect the backplane connectors on the replacement card for clean, undamaged pins.
- Align the board edges with the baseplate guide slots and slide the module inward until the faceplate levers engage.
- Push the locking levers firmly closed to seat the module into the backplane bus.
4
Power-On & Loop Commissioning
4.Power-On & Loop Commissioning:
- Restore power to the I/O rack and observe the front-panel diagnostic LEDs (POWER, RUN, FAULT).
- Verify module status and HART channel pass-through in the Metso DNA Engineering Environment software.
- Inject test command values (4 mA, 12 mA, 20 mA) to verify connected valve positioner movement and feedback accuracy.
Firmware/Software Versions & Upgrade Notes
- System Engineering Configuration: The card requires correct I/O address mapping and channel parameter setup in the Metso DNA Explorer / Engineering software suite. Ensure channel modes (0–20 mA vs. 4–20 mA) match field device specifications.
- HART Pass-Through Enabling: To utilize smart valve diagnostics, verify that HART pass-through communication is enabled in the I/O channel properties within the control environment.
- Redundancy & Baseplate Rules: If installing in a redundant I/O configuration, ensure both primary and secondary cards share identical hardware revision levels to ensure smooth automated failover.
Frequently Asked Questions (FAQ)
Is this Metso module genuine OEM and completely unused?
Yes. This module is New Surplus (Original New). It is authentic Metso / Valmet inventory sourced from canceled plant expansion projects or strategic maintenance overstock. It has never been deployed in active process loops.
Why choose New Surplus over a refurbished Metso I/O card?
Continuous-process control cabinets subject electronics to ambient heat and chemical vapors. Refurbished I/O cards often feature aged capacitors and degraded optocouplers that cause current output drift or intermittent HART signal dropouts. New Surplus guarantees factory-original component lifespan and 100% calibration accuracy out of the box.
Can the card operate without HART instruments connected?
Yes. The functions as a standard, high-accuracy 4–20 mA analog output card for conventional non-HART actuators. The HART overlay function operates independently without disturbing standard analog current loop signals.
Can I hot-swap this module in a live Metso DNA rack?
Hot-swapping depends on the specific baseplate design and cabinet redundancy setup. While Metso DNA baseplates generally support live insertion, removing an active single-card will cause an immediate loss of control signal to all 4 connected field valves. Always follow site-specific safety protocols before servicing live I/O cards.
What warranty coverage is provided with this product?
We back this unit with a 1-Year Comprehensive Replacement Warranty. Every Metso card undergoes visual inspection, backplane power validation, and channel continuity testing prior to shipment.
