Component Snapshot At-a-Glance
- Model: 3008N
- Alt. P/N: Base model 3008; N = full conformal coated harsh environment variant
- Product Series: Triconex Tricon TMR Safety Instrumented System (SIS)
- Hardware Type: Rack-mounted triple redundant main processor (MP) module
- Key Feature: Triple independent MPC860 CPU legs, 25Mbps TriBus backplane, coated PCB for high humidity/salt fog offshore cabinets
- Primary Field Use: Executes SIL3 safety shutdown logic, votes TMR I/O data, hosts TriStation control program, communicates with HMI and field I/O modules.
Hard-Numbers: Technical Specifications
- Protocol Support: TriBus proprietary backplane bus, Modbus TCP/RTU, TriStation configuration protocol
- Port Count: Front panel Ethernet, serial config port, TriBus backplane edge connector
- TriBus Data Rate: 25 Mbps synchronous rack bus
- Operating Temperature: 0°C to +60°C operational; -40°C to +70°C storage
- Isolation Rating: 1000V galvanic isolation between communication ports and TMR logic cores
- Power Draw: 5VDC rack backplane, max 18W per module
- CPU Core: 3× Motorola MPC860 32-bit RISC, 50MHz per redundant leg
- Memory: 16MB DRAM, 32KB lithium battery-backed SRAM, 6MB flash program storage
- Battery Retention: Minimum 12 months program retention with power removed
- Certifications: IEC 61508 SIL3, ATEX Zone 2, UL, CE, marine/offshore conformal coating rating
- Hot-Swap Capable: Yes, TriBus hold-up circuit prevents rack fault during live replacement
- Dimensions (H×W×D): 405mm × 22mm × 400mm
- Weight: 2.12kg
The Real-World Problem It Solves
Uncoated base 3008 CPU boards suffer rapid corrosion in offshore FPSO and coastal refinery salt fog environments. Single-core non-TMR controllers create unmitigated single-point failures that violate SIL3 safety compliance during emergency shutdown events.Where you’ll typically find it:
- Refinery ESD emergency shutdown racks for reactor, distillation and flare safety interlocks
- Offshore drilling rig & FPSO fire & gas (F&G) high-integrity safety control cabinets
- Fossil power plant boiler and turbine safety instrumented systems
This triple redundant coated main processor eliminates single CPU failure risks and resists corrosive plant air to extend service life in harsh industrial sites.
Hardware Architecture & Under-the-Hood Logic
Three fully independent identical CPU processing legs (TMR triple modular redundancy); every logic scan, I/O read and output command undergoes hardware two-out-of-three voting to suppress single leg faults.
- Rack backplane 5VDC feeds isolated power rails to each of the three separate CPU core assemblies.
- 50MHz MPC860 processors run identical safety logic scan cycles synchronously every 10ms.
- 25Mbps TriBus backplane synchronously polls all analog/digital I/O modules for field sensor data.
- Hardware voting logic compares results from three CPU legs; mismatched single leg flagged as fault without interrupting safety execution.
- Front panel Ethernet transmits alarm, SOE and process values to plant DCS and operator HMIs.
- Internal lithium battery retains SRAM tag data and program configuration during full rack power loss.
- Conformal coating covers all PCB traces and components to block salt dust, moisture and chemical vapor corrosion.
Field Service Pitfalls: What Rookies Get Wrong
Mismatched firmware revision across triple redundant CPU setsTechs swap one 3008N without flashing matching firmware to the other two processors. Cross-leg voting mismatch triggers constant MAJOR FAULT rack alarms and partial safety logic suspension.
- Field Rule: Load identical TriStation firmware revision to all three redundant MPs; verify sync PASS LED steady green before returning to service.
Expired internal lithium battery causing total program loss on power outageMaintenance crews skip battery replacement for over 12 months. Full rack power cycle erases SRAM tag data and safety logic, requiring full program reload from backup media.
- Quick Fix: Replace internal lithium battery every 10 months; perform battery swap while rack remains powered to preserve memory state.
Blocking rack side ventilation with dense cable bundlesStacking high-wattage power supply and I/O modules adjacent to 3008N blocks chassis airflow. Internal heat pushes operating temperature above 60°C, triggering CPU thermal throttling and intermittent TriBus communication timeouts.
- Field Rule: Maintain minimum 30mm vertical clearance top and bottom of CPU slot; clean cabinet intake air filters monthly to remove salt dust buildup.
Commercial Availability & Pricing Note
Please note: The listed price is for reference only and is not binding. Final pricing and terms are subject to negotiation based on current market conditions and availability.
