2. Model Definition

1. 51304638: Base model for 16-channel non-isolated HART analog output FTA

2. -375: Ultra heavy-duty extreme harsh industrial PCB grade

   • Ultra-thick full-board reinforced conformal coating, superior resistance to high humidity, heavy dust, salt mist and strong corrosive chemical vapors

   • Ultra-high-capacity bidirectional TVS + gas discharge tube hybrid surge suppression (lightning transient rated) per channel

   • Four-stage cascaded differential RC EMI filter network, precision tuned to preserve full HART signal amplitude with zero attenuation under extreme high-noise conditions

   • Oversized high-power flyback freewheeling diode arrays for large inductive actuator coil back-EMF full dissipation

   • Ultra-low-tolerance precision series damping resistors for perfectly matched 4–20mA linearity across all channels

   • Extra-wide reinforced physical channel isolation partitions to eliminate cross-channel signal leakage and crosstalk

   • Nickel-plated compression screw terminals and PCB solder pads to resist oxidation, salt fog and chemical corrosion long-term

3. Matched IOP Hardware: Honeywell 16-channel non-isolated HART 4–20mA analog output UCN IOP card

4. Incompatible Hardware: Isolated HART AO FTAs, AI FTAs, discrete DI/DO, TC/RTD LLAI, pulse counter, serial communication termination blocks

3. Technical Specifications

1. Channel Count: 16 independent non-isolated HART 4–20mA analog output channels

2. Supported Field Loads

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

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

3. FTA Structure: Fully passive termination block with no onboard power supply; integrated per-channel HART coupling, multi-stage filtering, hybrid surge protection and high-power inductive kickback suppression

4. PCB Protection: Ultra-thick reinforced conformal coating; flammability UL94 V0

5. Terminal Type: Nickel-plated compression screw terminals, compatible with solid/stranded copper wire up to 14 AWG

6. Form Factor: Standard Size B footprint, snap-on DIN rail mount for 35 mm standard rails

7. Operating Ambient: 0℃ ~ +60℃ indoor cabinet only; maximum humidity, dust, salt fog and corrosion tolerance within the 51304638 product line

8. Circuit Architecture

   • Four-stage low-pass EMI filtering to suppress extreme switching noise from large VFD banks, MCCs, medium-voltage switchgear and large motor control centers

   • Hybrid TVS+GDT ultra-high-energy bidirectional surge suppression on Ch+ and loop return lines for lightning-induced transients

   • High-power flyback diodes to eliminate large inductive coil back-EMF spikes from heavy actuator loads

   • Low-ESR ultra-stable coupling capacitors to maintain full HART signal swing over long, high-capacitance field cables

   • Tightly calibrated damping resistors to eliminate valve hunting and guarantee uniform stroke response across all 16 loops

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

9. Redundancy Compatibility: Fully supports primary/standby redundant non-isolated HART AO IOP architecture; hot-swap IOP card replacement permitted

10. Approximate Unit Weight: 0.362 kg

4. Interface & Communication Configuration

1. Inner IOP Connection: Locking heavy-duty flat ribbon cable connector directly mates to non-isolated HART AO IOP pin headers. Heavy reinforced cable strain relief prevents pin header deformation or fracture under sustained tension of long field multi-core wiring harnesses. Combined DC 4–20mA drive + superimposed HART AC signals pass through four-stage filters and hybrid lightning-grade surge networks to field load terminals. The HART AO IOP generates analog setpoint drive levels, processes bidirectional HART command/response frames, and transmits valve position, stroke, fault and calibration diagnostic data to Experion PKS controller over the UCN bus.

2. Field Outer Terminals: Each channel features independent nickel-plated Ch+ / Loop– terminals for two-wire actuator wiring; loop drive power is sourced entirely from the paired non-isolated HART AO IOP through FTA passive protection networks.

3. Drive Power Source: Regulated 4–20mA drive power supplied exclusively by the HART analog output IOP card.

5. Core Functions

1. Cable Strain Relief: Heavy-duty reinforced strain relief safeguards fragile HART AO IOP pin headers from mechanical stress, bending and fatigue fracture caused by continuous pulling force of long multi-core field control cables.

2. Four-Stage Extreme EMI Noise Rejection: Four-layer cascaded filter architecture drastically outperforms -100/-125/-150/-200 grades, completely eliminating valve hunting, setpoint drift, HART poll timeouts and diagnostic dropouts in extreme high-noise motor/VFD and power switchgear zones while preserving full HART communication bandwidth.

3. Ultra-Heavy Lightning-Grade Surge & Inductive Kickback Protection: Hybrid TVS+GDT surge stack absorbs intense lightning-induced transients, large wiring short spikes and heavy switching arcs; oversized flyback diodes fully dissipate high-inductance coil back-EMF, delivering maximum protection for sensitive HART AO IOP output drive semiconductors.

4. Ultra Heavy-Duty Anti-Corrosion & Anti-Oxidation Environmental Barrier: Ultra-thick conformal coating fully encapsulates PCB substrate, traces and passive components; nickel-plated terminals and solder pads resist oxidation, salt fog and strong chemical fumes, delivering multi-year stable operation in coastal, offshore, fertilizer and heavy chemical cabinet atmospheres.

5. Uniform Loop Drive & HART Channel Consistency: Precision ultra-tight tolerance damping resistors and coupling capacitors deliver identical drive strength, pull-in speed, analog linearity and HART signal gain across all 16 output channels for perfectly matched valve and actuator stroke performance.

6. Independent Single-Channel Maintenance: Nickel-plated isolated terminal blocks support HART positioner/I/P replacement, full loop resistance/insulation testing, handheld HART communicator connection and fault troubleshooting for one control loop without disrupting the other 15 critical safety, process and interlock output circuits.

7. Redundancy Hot-Swap Capability: Standby redundant non-isolated HART AO IOP cards can be replaced online without losing critical shutoff valve actuation, flow/pressure level setpoints, safety trip relays, emergency alarm outputs or burner control actuator power.

6. Application Scenarios

Applicable Industries

Non-Isolated HART Analog Control Loops

Cabinet Deployment

7. Wiring, Operation & Maintenance Guidelines

Wiring Standards

1. Two-wire actuator wiring: Actuator positive → nickel-plated FTA Ch+, actuator negative → FTA Loop–; reversed polarity severely degrades kickback diode performance and accelerates component aging/corrosion.

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

3. Use high-grade shielded twisted-pair low-capacitance instrument cable for all field runs; implement single-point shield grounding only at DCS cabinet FTA side to eliminate ground loop noise and HART communication instability.

4. Route HART AO analog cables physically separated from high-current AC power, MCC and VFD output wiring; maintain maximum practical separation from large motor power feeders to minimize EMI coupling interference.

Spare Part Interchangeability

Standard Fault Troubleshooting Flow