2. Model Definition

51304648: Base model for 16-channel galvanically isolated HART analog output FTA

-200: Medium heavy-duty reinforced PCB grade

Medium-thick reinforced full-board conformal coating with greatly improved resistance to high humidity, heavy dust and weak-to-mild corrosive gas

High-capacity bidirectional TVS surge suppression for transients, ESD and line faults with higher impact energy tolerance than -100/-125/-175

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

Independent full per-channel galvanic isolation barriers to completely eliminate field-DCS ground loop circulating currents

Oversized reinforced flyback freewheeling diode arrays for full dissipation of back-EMF spikes from large inductive actuator coils

Ultra-tight tolerance isolated damping resistors for highly consistent 4–20mA linearity across all channels

Extra-thick reinforced physical channel isolation partitions to eliminate analog/HART signal crosstalk and leakage between channels

3. Technical Specifications

Channel Count: 16 fully independent channels with full galvanic isolation per channel

Compatible Field Devices

Two-wire HART smart valve positioners, heavy-duty electro-pneumatic HART I/P transducers, linear/rotary HART modulating actuators

Backward compatible with conventional non-HART 4–20mA I/P transducers and pneumatic valve positioners

FTA Structure: Passive isolated termination board without built-in power supply; integrated per-channel HART coupling, three-stage filtering, surge protection and high-power inductive kickback suppression

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

Terminal Type: Compression screw terminals compatible with solid/stranded copper wire up to 14 AWG; independent isolated positive/negative terminal pair for each channel

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

Operating Ambient: 0℃ ~ +60℃ indoor cabinet; superior tolerance for humidity, dust and mild corrosion versus -100/-125/-175; not designed for continuous salt fog environments (select -325/-375 for salt fog)

Circuit Architecture Parameters

Three-stage low-pass differential filtering precisely tuned to preserve full HART carrier amplitude without attenuation

High-energy bidirectional TVS suppresses positive/negative transient high voltage on output loops

Galvanic isolation barrier eliminates measurement drift and HART disconnection caused by ground potential offset

Low-ESR precision coupling capacitors maintain full HART signal swing without DC drive power loss

High-power flyback diodes eliminate large back-EMF voltage spikes from inductive actuator loads

Calibrated ultra-low-tolerance damping resistors suppress valve hunting and deliver uniform actuator pull-in current and linear stroke response

Extra-thick isolation partitions fully block inter-channel analog bleed and HART signal interference

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

Approximate Unit Weight: 0.360 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking heavy-duty flat ribbon cable directly mates to isolated HART AO IOP pin headers. Reinforced cable strain relief prevents pin header deformation or fracture under sustained tension of long multi-core field control wiring harnesses.

Field Outer Terminals: Independent isolated Ch+ / Loop– terminals for each two-wire HART actuator loop; field drive circuit fully galvanically separated from DCS control ground potential.

Communication Mechanism: 4–20mA DC drive superimposed with FSK HART digital signals via frequency division. The FTA acts only as passive coupling and filtering component without altering HART timing or protocol.

No extra communication port: HART communicator connects directly across Ch+ and Loop– field terminals for commissioning and diagnostics.

5. Core Functions

Full per-channel galvanic isolation: Eliminates circulating ground loop currents at multi-ground sites, resolving unstable valve stroke and frequent HART communication timeouts.

Three-stage heavy EMI noise rejection: Suppresses strong electromagnetic interference from large VFD systems, MCCs and medium-voltage switchgear to eliminate valve hunting, setpoint drift and repeated HART poll retries.

High-energy surge & short-circuit protection: Withstands lightning-induced transients, startup surges and short-circuit fault high voltage to protect costly IOP output drive circuits.

High-power inductive kickback suppression: Rapidly dissipates back-EMF from solenoid and large-coil positioners to extend service life of IOP and field equipment.

Stable HART communication coupling: Low-distortion capacitor arrays sustain reliable HART handshaking, parameter reading/writing and diagnostic uploading over long field cables.

Uniform output linear calibration: High-precision damping resistors deliver matched drive characteristics across all 16 channels to reduce bulk calibration workload.

Multi-device backward compatibility: Supports mixed installation of HART smart and conventional non-HART 4–20mA loads within the same cabinet.

Redundant hot maintenance: Seamlessly follows primary/standby IOP switching; single-channel disconnection and troubleshooting do not affect the other 15 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 process shutoff HART smart valve positioners

High-pressure throttle modulating HART actuators

Furnace draft large damper HART I/P transducers

Blending control valve smart positioners

Pressure reduction HART modulating actuators

Suitable for multi-ground plant layouts, VFD-dense process areas, cabinets with long-term high humidity and dust accumulation, and atmospheres with faint weak acid/alkaline volatile vapors. Not applicable for coastal continuous salt fog or strong-acid heavy chemical workshops (upgrade to -325/-375 for such harsh conditions).

7. Wiring Standards

Two-wire actuator wiring: Actuator positive → isolated FTA Ch+, actuator negative → isolated Loop–; reversed polarity weakens kickback protection and slightly degrades HART waveform quality.

HART communicator connection: Clamp test leads directly across isolated Ch+ / Loop– terminals at FTA or valve positioner; no external load resistor required for standard two-wire isolated HART AO loops.

Cable selection: Shielded twisted-pair instrument cable for all field runs; shield grounded only once at DCS cabinet FTA side with field end left ungrounded to fully suppress ground loop noise.

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

8. Incompatible Hardware

Non-isolated HART AO (51304638), isolated non-HART AO (51304640), isolated HART AI (51304644), all non-HART AI FTAs, discrete DI/DO termination boards, TC/RTD temperature FTAs, pulse counter and serial communication termination blocks cannot pair with this IOP card.