2. Model Definition

51304730: Base model for 16-channel galvanically isolated non-HART analog output FTA

-175: Medium heavy-duty reinforced PCB protection grade

Medium-thick reinforced full-board conformal coating, enhanced resistance to high humidity, heavy dust and mild-moderate corrosive gas

High-capacity bidirectional TVS surge suppression for transients, ESD and line faults, higher energy withstand than -100/-125, per-channel isolated protection

Three-stage cascaded RC differential EMI filter optimized for high-noise plant areas with dense MCC and large VFD clusters

Independent galvanic isolation barrier for each channel, no electrical connection between field loop and DCS ground

Oversized reinforced flyback freewheeling diode arrays to fully dissipate large inductive coil back-EMF spikes

Precision tight-tolerance series damping resistors for uniform full-range 4–20mA linear stroke response across all channels

Extra-thick reinforced plastic channel baffles to eliminate inter-channel analog signal leakage and crosstalk

3. Technical Specifications

Channel Count: 16 fully independent output loops, complete galvanic isolation per channel

Compatible Field Devices

Two-wire non-HART 4–20mA loads: heavy-duty electro-pneumatic I/P converters, pneumatic valve positioners, linear/rotary modulating solenoid actuators

FTA Structure: Passive isolated termination board with no built-in power supply; integrated three-stage differential filtering, high-energy surge protection and heavy inductive kickback suppression, no HART coupling circuit

PCB Protection: Medium-thick reinforced conformal coating; flammability UL94 V0

Terminal Type: Compression screw terminals for solid/stranded copper wire up to 14 AWG; each channel has isolated Ch+ / Loop– field terminals fully separated from DCS ground and adjacent channels

Form Factor: Standard B-size footprint, snap-on DIN rail mounting for 35 mm standard rails

Operating Ambient: 0℃ ~ +60℃ indoor cabinet; better humidity, dust and mild corrosion resistance than -100/-125; not designed for continuous salt fog environments

Circuit Architecture Parameters

Three-stage low-pass differential filtering suppresses severe EMI from large VFD systems, MCCs and medium-voltage switchgear

High-energy bidirectional TVS clamps positive/negative transient high voltage on each isolated output loop

Per-channel galvanic isolation completely eliminates valve stroke drift caused by field-DCS ground potential offset

Tight-tolerance damping resistors fully eliminate valve hunting and stabilize full-span 4–20mA linear output

Oversized flyback diodes rapidly absorb severe back-EMF from heavy inductive actuator coils

Extra-thick baffles fully block inter-channel analog bleed and cross-loop interference

Redundancy Support: Fully compatible with primary/standby redundant isolated non-HART AO IOP; hot-swap FTA replacement allowed without process shutdown

Approximate Unit Weight: 0.360 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking heavy-duty flat ribbon cable directly mates to isolated non-HART AO IOP pin headers. Reinforced cable strain relief prevents pin deformation/fracture under long-term sustained wiring harness tension.

Field Outer Terminals: 16 groups of independent isolated Ch+ / Loop– terminals; each loop is electrically isolated from DCS ground and neighboring channels.

Signal Mechanism: Pure 4–20mA DC analog drive signals; no HART circuit integrated.

No auxiliary communication ports, only analog control signal transmission supported.

5. Core Functions

Full per-channel galvanic isolation: Eliminates ground loop interference, stable operation for both multi-ground complex plants and single-ground layouts.

Three-stage heavy EMI noise rejection: Suppresses intense electromagnetic interference from VFD banks, MCCs and medium-voltage switchgear to remove valve hunting and setpoint fluctuation.

High-energy surge & inductive kickback protection: Withstands lightning transients, startup surges and short-circuit voltage spikes to protect sensitive IOP output power stages and field actuators.

Uniform linear output performance: Precision matched passive components deliver consistent valve stroke response across all 16 channels to simplify calibration work.

Strong inter-channel signal separation: Extra-thick partition baffles greatly reduce analog crosstalk between adjacent control loops.

Redundant hot-swappable maintenance: Automatically synchronizes with primary/standby IOP switching; single-channel troubleshooting does not affect the other 15 control loops.

6. Application Scenarios

Applicable Industries

Petrochemical complexes, medium-heavy chemical plants, combined heat & power stations, large oil & gas refineries, pulp & paper mills, high-humidity wastewater treatment, medium-to-high humidity pharmaceutical batch production lines

Typical Control Loops

Emergency safety shutoff valves with heavy-duty conventional I/P positioners

High-pressure throttle modulating non-HART actuators

Large furnace draft air damper heavy-load I/P transducers

Process blending loop standard 4–20mA modulating valves

Pressure reduction conventional control valve actuators

Suitable for multi-ground and single-ground plant layouts, VFD-dense high-noise zones, cabinets with long-term high humidity and heavy dust accumulation, atmospheres with mild-moderate acidic/alkaline volatile vapors. Not suitable for offshore platforms or coastal locations with continuous heavy salt fog exposure.

7. Wiring Standards

Two-wire actuator wiring: Actuator positive → isolated FTA Ch+, actuator negative → FTA Loop–; reversed polarity weakens kickback suppression efficiency and creates measurable stroke offset.

Cable specification: Shielded twisted-pair instrument cable for all field wiring runs; cable shield grounded solely at DCS cabinet FTA side, field end ungrounded to suppress residual noise.

Power cable segregation: Physically separate analog control cables from high-voltage AC power, MCC and VFD output wiring to minimize EMI coupling.

8. Incompatible Hardware

All non-isolated AI/AO FTAs (51304718, 51304685, 51304672, 51304690), isolated HART AI (51304644), isolated non-HART AI (51304650), isolated HART AO (51304728), discrete DI/DO termination boards, TC/RTD dedicated FTAs, pulse counter and serial communication terminal assemblies cannot be paired with this isolated non-HART AO IOP card.