2. Model Definition

51304685: Base model for 16-channel non-isolated HART analog input FTA

-100: Standard baseline PCB grade

Basic full-board moisture & dust resistant conformal coating for dry clean cabinet environments

Standard bidirectional TVS transient, ESD surge protection per channel (no channel isolation)

Single-stage RC low-pass EMI filter tuned to preserve HART carrier signal without attenuation

Global common ground bus across all 16 channels, no independent galvanic isolation barriers

Standard capacity loop current limiting resistors for short-circuit overload protection of transmitters and IOP inputs

Basic plastic partition baffles to reduce mild inter-channel analog/HART signal crosstalk

3. Technical Specifications

Channel Count: 16 shared-ground channels, no per-channel galvanic isolation

Compatible Field Devices

Two-wire HART smart transmitters: pressure, differential pressure, flow, level, RTD/TC temperature, pH, ORP, dissolved oxygen, conductivity analytical transmitters

Backward compatible with conventional non-HART 4–20mA two-wire transmitters

FTA Structure: Passive non-isolated termination board without built-in power supply; integrated single-stage HART coupling, filtering, standard surge protection and short-circuit current limiting

PCB Protection: Basic standard conformal coating; flammability UL94 V0

Terminal Type: Compression screw terminals compatible with solid/stranded copper wire up to 14 AWG; each channel has Ch+ / Loop– terminals sharing a unified ground bus

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

Operating Ambient: 0℃ ~ +60℃ clean indoor cabinet; only suitable for dry, low-dust, non-corrosive single-ground layouts; unsuitable for multi-ground sites, salt fog or chemical fume atmospheres

Circuit Architecture Parameters

Single-stage low-pass filtering calibrated to retain full HART signal amplitude

Standard bidirectional TVS suppresses positive/negative transient high voltage on each input loop

Common ground structure; ground potential differences between field and DCS will cause measurement drift and HART communication instability

Calibrated standard-tolerance current-limit resistors prevent transmitter burnout and IOP input damage during field short faults

Basic partition baffles minimize slight inter-channel analog bleed and HART crosstalk

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

Approximate Unit Weight: 0.356 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking flat ribbon cable directly mates to non-isolated HART AI IOP pin headers. Standard cable strain relief prevents pin header deformation under routine wiring harness tension.

Field Outer Terminals: 16 groups of Ch+ / Loop– terminals with a shared common ground bus across all channels; field excitation circuit shares DCS control ground potential.

Signal Mechanism: 4–20mA DC analog measurement with superimposed FSK HART digital signals via frequency division; passive HART coupling built into each channel.

HART Access: Handheld HART communicator clamps directly across Ch+ and Loop– field terminals for calibration and diagnostics; no extra external port required.

5. Core Functions

Common-ground HART signal routing: Cost-effective single-ground layout supporting both HART smart and standard 4–20mA transmitters.

Single-stage basic HART EMI noise rejection: Reduces minor measurement jitter and slight HART retries in low-noise clean cabinet environments.

Standard surge & short-circuit protection: Shields IOP high-impedance inputs and field transmitters from low-magnitude wiring transients and short-circuit overload.

Uniform loop overload protection: Matched current limiting resistors deliver consistent short-circuit protection for all connected transmitters.

Consistent input linearity & HART matching: Balanced passive components ensure uniform measurement response and stable HART handshake across all 16 channels for easy calibration.

Redundant hot maintenance: Seamlessly follows primary/standby IOP switching; single-channel disconnection does not affect remaining 15 measurement loops.

6. Application Scenarios

Applicable Industries

Light manufacturing, municipal clean water treatment, low-noise auxiliary petrochemical facilities, standard low-humidity pharmaceutical batch production

Typical Measurement Loops

General pressure and differential pressure HART smart transmitters

Conventional/HART hybrid flow measurement transmitters

Atmospheric tank level monitoring transmitters

Standard RTD/TC temperature transmitters

Clean water pH and conductivity analytical transmitters

Only applicable to single-ground control room layouts, low-VFD low-noise process areas, dry dust-free cabinet atmospheres. Not usable for multi-ground sites, high-humidity, dusty, corrosive or salt-fog cabinet environments.

7. Wiring Standards

Two-wire transmitter wiring: Transmitter positive → FTA Ch+, transmitter negative → FTA Loop– (common ground bus); reversed polarity creates obvious measurement offset and degraded HART waveform.

Cable selection: Shielded twisted-pair instrument cable for all field runs; shield grounded once at DCS cabinet FTA side.

Power cable separation: Maintain physical separation between analog instrument cables and high-voltage AC power wiring to reduce EMI coupling.

8. Incompatible Hardware

All isolated AI/AO FTAs (51304644, 51304640, 51304648, 51304650), non-isolated non-HART AI (51304672), non-isolated AO FTAs, discrete DI/DO termination boards, dedicated TC/RTD FTAs, pulse counter and serial communication terminal assemblies cannot pair with this non-isolated HART AI IOP card.