Application Scenarios
In a refinery fluid catalytic cracking (FCC) unit, dozens of control valves modulate feed rate, riser temperature, and product split—all driven by analog output signals from the DCS. A single failed AO channel can drift a valve off-setpoint, triggering a cascade of alarms and potentially forcing a unit shutdown. By deploying the 8C-TAOX51 in the Experion PKS Series 8 I/O rack, the plant gains sixteen independent, channel-to-backplane isolated 4-20 mA outputs in one compact IOTA slot. When a channel fault occurs, the 8C-TAOX51’s integrated diagnostics instantly report open-circuit, short-circuit, or output deviation to the C300, and maintenance can hot-swap the module without powering down the rack—turning what used to be a multi-hour emergency response into a five-minute planned intervention.
Parameter
| Main Parameters | Value/Description |
|---|---|
| Product Model | 8C-TAOX51 |
| Part Number | 51306983-175 |
| Manufacturer | Honeywell |
| Product Category | 16-Channel Analog Output IOTA |
| System Compatibility | Experion PKS Series 8, C300 Controller, PlantCruise |
| Output Channels | 16 channels (independent) |
| Output Signal Type | 4-20 mA |
| Output Ripple | <100 mV peak-to-peak @ 250Ω load |
| Resolution | ±0.05% of Full Scale |
| Calibrated Accuracy | ±0.35% of Full Scale at 25°C |
| Temperature Drift | 0.005% FS / °C |
| Maximum Open Circuit Voltage | 22 V |
| Isolation | 1500 VDC (channel to backplane) |
| HART Support | Yes — pass-through on every channel |
| Power Supply | 24 VDC nominal (20-30 VDC range) |
| Redundancy | Non-Redundant (8C-TAOX51); 1:1 redundant available via 8C-TAOX61 |
| Hot-Swap | Yes — replace online without system shutdown |
| Operating Temperature | -40°C to +70°C |
| Certification | CE, UL, CSA, Class I Div 2 / Zone 2 |
| Country of Origin | USA |
Technical Principles and Innovative Values
Innovation Point 1 — 16-Channel High-Density AO in a Single IOTA: The 8C-TAOX51 packs sixteen independently configurable 4-20 mA outputs into one compact termination assembly, maximizing cabinet space efficiency and reducing per-point wiring cost versus discrete AO blocks.
Innovation Point 2 — Per-Channel HART Pass-Through: Every output on the 8C-TAOX51 integrates native HART communication, enabling remote configuration and diagnostics of smart field devices (valve positioners, VFDs, transmitters) without external HART multiplexers—simplifying asset management and reducing lifecycle cost.
Innovation Point 3 — 1500 VDC Channel-to-Backplane Isolation: The 8C- galvanically isolates each analog output loop from the system backplane, blocking ground-potential differences and eliminating ground-loop-induced signal distortion—critical in large, distributed process plants.
Innovation Point 4 — Configurable Fail-Safe Behavior: Each channel on the 8C- can be independently programmed to hold last value, drive to a low (safe) value, or drive to a high value upon module or power failure, ensuring the connected final control element defaults to the safest possible state.
Innovation Point 5 — Coated, Hazardous-Area-Ready Construction: With conformal coating and Class I Div 2 / Zone 2 certification, the 8C- withstands humidity, dust, chemicals, and temperature extremes while remaining suitable for non-incendive field deployments.
