Details

Introduction
The TB TACAN Unit Test Bench is a fully integrated, turnkey Factory Acceptance Testing (FAT) solution engineered by Neometrix Engineering for Moog Fernau’s TACAN 2010 “I-Level” navigation equipment. Replacing manual, error-prone procedures with automated, repeatable workflows, it validates all 25 functional modules—both intelligent μC-based units and passive RF components—against rigorous MIL-STD and IEC performance thresholds. This ensures rapid on-site commissioning, minimizes costly field rework, and provides complete traceability of test records for defense and aerospace customers.

Key Features
▹ Distributed μC Nodes in each module for localized data acquisition (voltage, current, RF power)
▹ High-Speed CAN-Bus communication at 1 Mbps for deterministic, low-latency control
▹ Quick-Connect RF/Power Looms (J1–J7) enabling tool-free fixture swaps and hot-swap capability
▹ Automated, Sequenced Test Scripts with built-in pass/fail logic and conditional branching
▹ Hot-Swappable Fixture Modules for rapid turnaround between module tests
▹ Remote Firmware Updates over secure Ethernet, minimizing bench downtime
▹ Integrated EMI/EMC Pre-Compliance Checks to catch potential electromagnetic issues early
▹ Throughput Optimization via parallel test lanes and multi-threaded execution

Applications
▹ Factory Acceptance Testing: Comprehensive validation of each TACAN module prior to shipment.
▹ Pre-Delivery Verification: Early identification of non-conformities to prevent installation delays.
▹ Operator Training & Certification: Standardized environment for hands-on qualification of maintenance and service personnel.
▹ Defense Navigation QA: Ensures bearing accuracy and signal stability for aircraft guidance systems.
▹ OEM Build Verification: Batch certification to reduce return rates and warranty costs.
▹ Regression Testing: Re-verifies module performance following firmware or software updates.
▹ EMI/EMC Compliance Checks: Pre-test screening against electromagnetic compatibility standards.
▹ Refurbishment Quality Control: Certification of overhauled or repaired units in service centers.

Technical Specification
Document Reference: T-PED-ATP-A2046-REV01
▹ System Model: TB_TACAN
▹ Modules Covered:
   • 12 Intelligent Modules (Transponder, LP/HPA, Keyer, Monitor, Receiver, Antenna Control)
   • 13 Passive Components (Power Supplies, Modem, Fan, Couplers, Filters, Detectors,
▹ Splitters, Combiners, Breakers, Backplanes, Status Panel)
▹ Data Interfaces: CAN 2.0B, USB 2.0, RS-232/485, Gigabit Ethernet
▹ RF Path: Quick-connect looms rated to 18 GHz with ≤0.5 dB insertion loss
▹ Power: 208–240 VAC input; regulated ±5 V, ±12 V, +28 V output rails
▹ Enclosure: 19′′ rack, 12 U height, 600 mm depth; forced-air, filtered cooling; EMI shielding
▹ Environmental: Operating 0–45 °C, 10–90 % RH; storage −20 °C to +70 °C
▹ Compliance: DGAQA Aeronautical Quality Assurance; IEC 61010-1; ANSI CAT II electrical safety  

System Architecture
A central ATE controller (rugged industrial PC) orchestrates tests via:
• Node Microcontrollers: ARM-class μCs embedded in intelligent modules for low-level measurements and health monitoring.
• CAN-Bus Network: Bi-directional communication reduces centralized wiring and supports real-time control.
• Quick-Connect Looms (J1–J7): Parallel RF/DC routing to passive modules, enabling hot-swap without rewiring.
• HMI Panel: 21′′ touchscreen for drag-and-drop fixture configuration, sequence editing, and live dashboards.

Principle of Operation
1. Boot & Self-Test: Controller verifies node firmware versions, performs built-in self-tests on μCs, and checks RF continuity.
2. Fixture Configuration: Operator selects the module under test; software activates relays and configures RF/power paths.
3. Stimulus Application: Precision RF sources sweep 962 ± 80 MHz at −30 dBm to +30 dBm; DC loads and TTL controls emulate operational conditions.
4. Data Acquisition: μC ADCs capture amplitude, phase, and VSWR with 1 μs timestamp resolution.
5. Pass/Fail Analysis: Measurements are compared against tolerance bands (±0.5 dB power, ±1 % VSWR); out-of-bounds results trigger retests or flag for inspection.

Workflow & Test Procedure
1. Setup Verification: Confirm calibration status; run continuity check on looms.
2. Detector Module Test: Connect J1/J2 looms, apply 970 MHz @ −10 dBm, verify DC detector output (1.2–1.4 V).
3. Amplifier Chain Validation: Sequentially power LPA then HPA; measure gain flatness (±0.5 dB) and harmonic suppression (≥60 dBc).
4. Interface & Keyer Checks: Emulate 270 Hz keying pulses; verify timing accuracy (±5 μs).
5. End-to-End Functional Test: Loopback transponder interrogation and response; confirm decoded bearing/range data.
6. Final Reporting: Auto-generate FAT report with operator and QA manager signature fields. 

Software Interface
• Drag-and-Drop Sequencer: Build or edit test flows without coding.
• Real-Time Dashboards: Multi-channel plots of RF parameters and error vector magnitude.
• Context-Sensitive Help: Integrated reference to MIL-STD-1760 and DO-160 procedures.
• Secure Data Management: Role-based access, SHA-256 report hashing, and optional encrypted backups.

Calibration
• Automated Routines: Utilize internal 10 MHz OCXO and 0 dB RF coupler to recalibrate ADCs, DACs, and temperature sensors.
• Traceability: Logs include date, technician ID, and reference standard serial numbers.
• Certificate Generation: ISO 17025-style PDF certificate appended to the FAT package.

Maintenance
• Preventive Schedule:
- Monthly: Airflow filter checks, loom retention tests, self-test run.
- Quarterly: Software patches, relay contact resistance verification (<50 mΩ), calibration drift checks (<±0.1 %).

• ESD Controls:
- Wrist-strap continuity, ionizer audits, antistatic flooring to protect μC modules.

• Field-Replaceable Units:
- Snap-in power supplies, fan assemblies, and RF couplers enable <30 min swap-out.

• Spare Kits: Optional pre-terminated looms, adapters, and quick-reference guides for rapid on-site repair.

Conclusion
The TB TACAN Unit Test Bench merges modular hardware, distributed intelligence, and sophisticated automation to deliver a best-in-class FAT solution for TACAN “I-Level” systems. Its comprehensive reporting, industry-compliant procedures, and scalable design empower OEMs and defense operators to certify navigation equipment with confidence—minimizing deployment risk, reducing time-to-mission, and ensuring long-term operational reliability.