Description
Application Scenarios
Picture a refinery control room operator monitoring hundreds of process variables across distillation columns, heat exchangers, and storage tanks. Each measurement—be it crude feed flow, column-top pressure, or bottoms level—originates from a field transmitter hundreds of meters away, often with different ground potentials and exposed to severe electrical noise. A single ground loop or common-mode voltage spike can corrupt an entire bank of readings, leading to false alarms, control instability, or even a costly shutdown.
By deploying the AAI143, the plant replaces vulnerable non-isolated I/O with 16 fully isolated 4–20 mA channels in a single FIO slot. Every channel is galvanically separated from the system backplane and from its neighbors, with 1500 V AC withstand capability. A fault on one transmitter—or a lightning-induced surge on one cable run—stays contained. The module’s built-in 19–25.5 V transmitter power supply also eliminates the need for external loop power supplies for 2-wire instruments, simplifying cabinet design and reducing wiring cost. For plants with smart HART transmitters, the AAI143-H variant adds digital diagnostics and remote configuration over the same two-wire loop, turning a simple measurement card into a predictive-maintenance enabler.
Parameter
| Main Parameters | Value / Description |
|---|---|
| Product Model | AAI143 (suffix defines variant, e.g. AAI143-S00/A4S00) |
| Manufacturer | Yokogawa Electric Corporation (Japan) |
| Product Category | Analog Input Module (FIO — Field Input/Output) |
| Number of Input Channels | 16 channels, galvanically isolated |
| Input Signal | 4 to 20 mA DC current loop |
| Allowable Input Current | 24 mA (overload tolerant without damage) |
| Input Resistance (Power ON) | 270 Ω @ 20 mA → 350 Ω @ 4 mA (dynamic, minimizes signal distortion) |
| Input Resistance (Power OFF) | 500 kΩ or larger (prevents leakage / ghost readings) |
| Accuracy | ±16 µA (±0.08 % of 20 mA full scale) |
| Data Update Period | 10 ms (real-time process loop ready) |
| Transmitter Power Supply | 19.0 V or higher @ 20 mA; ≤ 25.5 V @ 0 mA; 25 mA current limit |
| 2-Wire / 4-Wire Setting | Independently selectable per channel via hardware setting pin |
| Isolation (Withstanding Voltage) | 1500 V AC between input and system for 1 minute |
| Temperature Drift | ±16 µA per 10 °C ambient change |
| HART Communication | Available on -H suffix versions (HART 5/6/7 compatible) |
| External Connection | Pressure clamp terminal block, MIL connector cable, or dedicated KS1 cable |
| Current Consumption | 230 mA @ 5 V DC; 540 mA @ 24 V DC |
| Weight | Approx. 0.3 kg (module only); 0.4 kg with pressure clamp terminal block |
