2. Model Definition

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

-150: Medium reinforced PCB protection grade

Medium upgraded full-board conformal coating, superior resistance to humidity, dust and weak corrosive vapors compared to -100

Moderate high-energy bidirectional TVS transient, ESD and line fault surge protection (no channel isolation)

Dual-stage cascaded RC low-pass EMI filter precisely tuned to retain full HART carrier amplitude without attenuation

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

Precision matched loop current limiting resistors for uniform short-circuit overload protection of transmitters and IOP inputs

Thickened plastic channel baffles to mitigate inter-channel analog and HART signal crosstalk & leakage

3. Technical Specifications

Channel Count: 16 common-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 per-channel HART coupling, dual-stage filtering, medium-energy surge protection and short-circuit current limiting

PCB Protection: Medium upgraded conformal coating; flammability UL94 V0

Terminal Type: Compression screw terminals for solid/stranded copper wire up to 14 AWG; each channel has Ch+ / Loop–, all channels share one unified ground bus

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

Operating Ambient: 0℃ ~ +60℃ indoor cabinet; wider tolerance for humidity, dust and weak corrosion than -100; not suitable for salt fog or strong corrosive fume environments

Circuit Architecture Parameters

Dual-stage low-pass filtering suppresses medium-level EMI from VFD and motor control center equipment while preserving HART waveform integrity

Medium-energy bidirectional TVS clamps positive/negative transient high voltage on every input loop

Shared common ground design; ground potential differences between field and DCS cause measurement drift and unstable HART communication

Tight-tolerance current-limit resistors prevent transmitter burnout and IOP high-impedance input damage under field short faults

Thickened baffles reduce inter-channel analog bleed and HART signal interference

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

Approximate Unit Weight: 0.357 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking flat ribbon cable directly connects to non-isolated HART AI IOP pin headers. Reinforced cable strain relief avoids pin deformation under sustained wiring harness tension.

Field Outer Terminals: 16 groups of Ch+ / Loop– terminals sharing a global common ground bus; field excitation circuit runs on the same ground potential as the DCS control side.

Signal Mechanism: 4–20mA DC analog measurement signals overlaid with FSK HART digital signals via frequency division; passive HART coupling integrated per channel.

HART Access: Handheld HART communicator clamps directly across Ch+ and Loop– field terminals for commissioning, calibration and diagnostic reading; no dedicated auxiliary communication port.

5. Core Functions

Cost-effective common-ground HART signal transmission: Optimized for single-ground plant control rooms, supporting mixed installation of HART smart and conventional 4–20mA transmitters.

Dual-stage medium EMI noise suppression: Reduces moderate electromagnetic interference from VFD and MCC units to stabilize PV readings and cut down HART communication retries.

Medium-strength surge & short-circuit protection: Absorbs larger wiring transients and switching arcs to protect sensitive high-impedance IOP inputs and field transmitters.

Consistent loop overload safeguard: Uniform current limiting prevents transmitter damage once field wiring is accidentally shorted.

Balanced input linearity & HART matching: Matched passive components deliver consistent measurement response and stable HART handshake across all 16 channels to simplify calibration.

Redundant hot-swappable operation: Automatically adapts to primary/standby IOP switching; disconnecting and troubleshooting one channel will not disturb the other 15 measurement loops.

6. Application Scenarios

Applicable Industries

General petrochemical auxiliary areas, medium chemical plants, standard power plant auxiliary monitoring, municipal wastewater treatment, mild-humidity pharmaceutical production lines

Typical Measurement Loops

General process pressure and differential pressure HART transmitters

Hybrid HART/standard flow transmitters

Atmospheric storage tank level transmitters

Standard RTD/TC temperature transmitters

Water pH and conductivity analytical transmitters

Fit for single-ground plant layouts, medium-noise VFD zones, cabinets with mild elevated humidity and moderate dust accumulation, atmospheres with low-concentration weak acid/alkaline volatile vapors. Cannot be deployed in multi-ground sites, coastal salt fog zones and heavy corrosive chemical workshops.

7. Wiring Standards

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

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

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

8. Incompatible Hardware

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