2. Model Definition

51204172: Base part number for 8-channel analog output FTA

-175: Optimized PCB trace revision with full conformal protective coating

Matched IOP Card: MC-TAOY22 (8-point analog output IOP module)

Incompatible with DI, transistor DO, relay DO, HLAI and LLAI analog input FTA boards

3. Technical Specifications

Channel Count: 8 independent isolated analog output channels

Standard Output Signal: 4–20mA DC current control signal

PCB Protection: Complete conformal coating; flame retardant grade UL94 V0

Terminal Type: Compression screw terminals, applicable wire gauge up to 14 AWG (1.6 mm²)

Form Factor: Standard Size B, overall length 307 mm

Mounting Mode: Snap-on installation on standard 35 mm DIN rail

Operating Ambient: 0 ℃ ~ +60 ℃ (indoor control cabinet environment only)

Circuit Design: Passive circuit equipped with RC EMI filter and per-channel overload short-circuit protection

Redundancy Compatibility: Perfectly supports dual redundant MC-TAOY22 IOP card setup

Approximate Weight: ~0.328 kg

4. Interface & Communication Configuration

Inner Connection to IOP Card: Dedicated flat ribbon cable connector directly mates with MC-TAOY22 IOP card. There is no independent communication chip; control signals are delivered through the UCN control bus via the matched AO IOP module.

Outer Field Terminals: Polarity clearly marked positive and negative terminal blocks for each output control loop, arranged neatly for standardized control cable wiring.

Power Supply Reference: The cabinet’s 24VDC system power supplies the reference potential for each analog output loop.

5. Core Functions

Cable strain relief protects fragile pin headers on MC-TAOY22 IOP cards from mechanical damage caused by pulling tension of field control cables.

Onboard RC EMI filters suppress electromagnetic interference from motors, VFDs and contactors, stabilizing 4–20mA output signals to valve positioners and regulating actuators.

Independent per-channel overload limiting restricts fault current when field loops short-circuit, preventing burnout of the AO main card.

Full conformal coating insulates PCB circuits against moisture, dust and mild corrosive gas, extending service life in humid industrial cabinet conditions.

Optimized PCB layout improves heat dissipation and long-term circuit stability for continuous 24-hour operation.

Full HART protocol compatibility enables digital parameter calibration, fault diagnosis and status reading for smart valve positioners alongside conventional 4–20mA analog control.

Standardized terminal layout simplifies loop commissioning, signal calibration, wiring inspection and fault point troubleshooting.

6. Application Scenarios

Process industries adopting Honeywell Experion PKS UCN/C300 DCS: petrochemical, chemical plants, thermal power, oil & gas, pulp and paper, metallurgy, water treatment and pharmaceutical facilities.

Regulating control loops for control valves, electric actuators and variable regulators that receive 4–20mA command signals.

Standard supporting terminal assembly for 8-point analog output slots inside DCS I/O cabinets.

7. Operation & Maintenance Instructions

Matching Restriction: Only compatible with MC-TAOY22 analog output IOP card; cannot be replaced with digital I/O or analog input FTA units.

Wiring Specifications: Strictly follow positive/negative polarity printed on terminals; use shielded control cables with single-point shield grounding at the cabinet side to minimize signal noise.

Spare Part Interchangeability: 51204172-175, 51204172-125 and 51204172-100 have identical electrical characteristics and can be swapped urgently on site; using the same suffix model is recommended for long-term stable operation.

Standard Fault Troubleshooting Flow: No or abnormal output signal → Retighten compression terminal screws → Measure loop output current value → Check ribbon cable plugging tightness → Diagnose operating status of paired MC-TAOY22 IOP card.