YOKOGAWA ASS9981DE-02 – Field Control Station CPU Module | CENTUM VP Platform
Engineering Background
The YOKOGAWA ASS9981DE-02 is the CPU module at the heart of the CENTUM VP Integrated Production Control System — YOKOGAWA’s flagship DCS platform deployed across oil & gas, petrochemical, power generation, and pharmaceutical industries worldwide. The CENTUM VP architecture is engineered for high-availability continuous process control, and the ASS9981DE-02 serves as the computational core of the Field Control Station (FCS): executing real-time control logic, managing I/O communication, and maintaining redundant system integrity across mission-critical installations.
Product Positioning
Targeted at procurement engineers and MRO (Maintenance, Repair & Operations) teams responsible for sustaining CENTUM VP installations, the ASS9981DE-02 is a direct OEM replacement module. It is suitable for both planned lifecycle upgrades and emergency spare-part procurement scenarios where system uptime is non-negotiable. Konmask.com maintains verified stock with full traceability documentation, enabling rapid response to both scheduled maintenance windows and unplanned outage events.
Complete Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | ASS9981DE-02 |
| Manufacturer | YOKOGAWA Electric Corporation |
| Module Type | CPU Module – Field Control Station (FCS) |
| Platform | CENTUM VP Integrated Production Control System |
| Form Factor | Rack-mount module (FCS chassis) |
| Communication Interface | Vnet/IP (Ethernet-based control bus, 100 Mbps) |
| Redundancy Support | Dual-redundant CPU (hot-standby, bumpless transfer) |
| Control Execution | Function blocks, SFC, sequence tables (IEC 61131-3 compliant) |
| I/O Support | Analog (AI/AO), Digital (DI/DO), HART, FOUNDATION Fieldbus, PROFIBUS |
| Operating Temperature | 0°C to 55°C (32°F to 131°F) |
| Storage Temperature | -25°C to 70°C |
| Relative Humidity | 5% to 95% RH (non-condensing) |
| Power Supply | Via FCS backplane (24 VDC nominal) |
| Weight | Approx. 900 g |
| Compliance | CE, UL, IECEx (refer to YOKOGAWA datasheet for full certifications) |
| RoHS Status | Compliant |
| MTBF | Refer to YOKOGAWA GS sheet (available on request) |
Proven Application Environments
- Oil & Gas: Upstream wellhead control, midstream pipeline SCADA integration, downstream refinery DCS backbone — where continuous uptime directly impacts production revenue.
- Petrochemical & Chemical: Continuous reactor control, distillation column automation, batch process sequencing with deterministic scan-cycle requirements.
- Power Generation: Boiler management systems, turbine control integration, grid-tie coordination — applications demanding sub-second fault response.
- Pharmaceutical & Life Sciences: FDA 21 CFR Part 11-compliant batch control, clean-room environment monitoring, audit-trail-ready process data logging.
- Pulp & Paper / Food & Beverage: High-throughput continuous process lines requiring deterministic scan times and minimal maintenance intervention.
- Water & Wastewater: Multi-site distributed control with centralized SCADA visibility via Vnet/IP backbone.
Engineering Advantages
- Deterministic Real-Time Execution: Consistent scan-cycle performance critical for tight PID loop control and safety interlock response — no jitter under full I/O load.
- Dual-Redundancy Architecture: Hot-standby CPU redundancy with seamless bumpless transfer on primary CPU fault — eliminates unplanned downtime without operator intervention.
- Vnet/IP Native Integration: Low-latency, high-bandwidth communication between FCS nodes and the Human Interface Station (HIS) — no protocol conversion overhead.
- IEC 61131-3 Compliant Programming: Full support for function block diagrams, sequential function charts, and structured text — compatible with existing CENTUM VP engineering libraries.
- Long-Term Platform Lifecycle: CENTUM VP is an actively supported platform under YOKOGAWA’s committed lifecycle policy — protecting capital investment in installed base through 2030+.
- Plug-and-Play Replacement: Direct module swap within existing FCS chassis — no re-engineering of I/O wiring or control logic required for like-for-like replacement.
- Fieldbus Protocol Support: Native HART, FOUNDATION Fieldbus, and PROFIBUS DP support enables integration with legacy and modern field instrumentation without additional gateways.
System Architecture & Signal Flow
Within the CENTUM VP architecture, the ASS9981DE-02 CPU module resides in the Field Control Station (FCS) chassis. Control logic — function blocks, sequence tables, SFC programs — is downloaded from the Engineering Workstation (EWS) via Vnet/IP. The CPU executes scan cycles, processes I/O data from connected I/O modules (analog, digital, HART, fieldbus), and communicates process values and alarms upstream to the Human Interface Station (HIS) and Plant Information Management System (PIMS) via the same Vnet/IP backbone. In redundant configurations, the secondary CPU module mirrors the primary in real time, ready for instantaneous bumpless takeover.
[EWS – Engineering Workstation]
│
Vnet/IP (100 Mbps Ethernet Control Bus)
│
[FCS Chassis – Field Control Station]
├── [ASS9981DE-02 CPU – Primary] ◄──► Hot Standby Sync
└── [ASS9981DE-02 CPU – Secondary (Redundant)]
│
[I/O Modules: AI / AO / DI / DO / HART / FOUNDATION Fieldbus / PROFIBUS]
│
[Field Instruments & Actuators – Sensors, Valves, Transmitters]
│
[HIS – Human Interface Station] ◄── Real-time process visualization
[PIMS – Plant Information Management System] ◄── Historian & reporting
Sourcing & Quality Verification
- Origin: Sourced from authorized YOKOGAWA distribution channels and verified MRO surplus with full traceability documentation — no grey-market or counterfeit risk.
- Inspection Protocol: Each unit undergoes visual inspection, firmware version verification, label authenticity check, and functional bench-test prior to shipment.
- Packaging: ESD-safe anti-static packaging with moisture barrier bag, desiccant, humidity indicator card, and shock-absorbing foam insert — compliant with IEC 61340-5-1.
- Documentation: Certificate of Conformance (CoC) and inspection report available upon request; YOKOGAWA original datasheet provided with shipment.
- Warranty: 12-month replacement warranty against manufacturing defects. Full warranty terms available at Konmask.com.
- Export Compliance: All shipments comply with applicable export control regulations (EAR/ECCN). End-user declaration may be required for certain destinations.
Procurement Process
- Confirm Part Number: Verify ASS9981DE-02 against your FCS chassis label, YOKOGAWA project BOM, and system revision documentation.
- Request Quote: Contact support@konmask.com with quantity, required delivery date, destination port, and CENTUM VP system revision.
- Order Confirmation: Receive proforma invoice with lead time, shipping terms (EXW / CIF / DDP available), and payment options (T/T, L/C, PayPal for qualified accounts).
- Quality Documentation: CoC and inspection test report issued with every shipment — no exceptions.
- Logistics: DHL Express / FedEx International Priority standard; air freight charter available for urgent AOG/plant-down requirements.
- After-Sales Support: Technical installation guidance, firmware compatibility advisory, and commissioning support provided post-delivery via dedicated engineering team.
Technical FAQ
Q: Is the ASS9981DE-02 compatible with earlier CENTUM CS 3000 systems?
A: The ASS9981DE-02 is designed for CENTUM VP. Compatibility with CS 3000 hardware is not guaranteed — consult YOKOGAWA’s migration documentation or contact our technical team for a compatibility assessment before ordering.
Q: Can this module be used in a non-redundant (simplex) FCS configuration?
A: Yes. The ASS9981DE-02 operates in both simplex and dual-redundant FCS configurations. Redundancy is enabled via system configuration in the EWS — no hardware modification required.
Q: What firmware version does the supplied unit carry?
A: Firmware versions vary by production batch. Please specify your current CENTUM VP system revision when ordering so we can match or advise on compatibility. Firmware upgrade support is available from our technical team.
Q: What is the typical lead time?
A: In-stock units ship within 2–5 business days. For units requiring sourcing, lead time is 2–4 weeks. Expedited options available — contact us immediately for plant-down or AOG situations.
Q: Do you provide installation and commissioning support?
A: Remote technical advisory is included with every order. On-site commissioning support can be arranged through our partner network — please inquire at the time of order placement.
Q: Can I return a module if it does not match my system requirements?
A: Returns are accepted within 30 days of delivery for unused, unopened units in original ESD packaging. Please contact support@konmask.com to initiate an RMA.
Q: Is a YOKOGAWA factory repair service available?
A: Konmask.com can facilitate factory repair and calibration through our YOKOGAWA service partner network. Lead times and pricing available on request.
© 2026 Konmask.com. All rights reserved.
Original Source: https://Konmask.com
Contact: support@konmask.com | +0086 19859288691
