2. Model Definition

51304736: Base model for 16-channel non-isolated non-HART analog input FTA

-175: Medium heavy-duty reinforced PCB protection grade

Medium-thick reinforced full-board conformal coating, improved resistance to high humidity, heavy dust and mild-moderate corrosive gas compared to -100/-125

High-capacity bidirectional TVS transient/ESD/line fault surge protection, no channel isolation, higher energy withstand than low grades

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

Global unified common ground bus for all 16 loops, no independent galvanic isolation between channels

Reinforced loop short-circuit current limiting resistors to protect transmitters and IOP input circuits

Precision tight-tolerance matched input impedance for consistent 4–20mA measurement accuracy across all channels

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

3. Technical Specifications

Channel Count: 16 common-ground input loops, no per-channel galvanic isolation

Compatible Field Devices

Two-wire non-HART 4–20mA transmitters: pressure, DP, flow, level, temperature, pH, DO, conductivity conventional transmitters

FTA Structure: Passive non-isolated termination board, no internal power supply; integrated three-stage differential filtering, high-energy surge protection, short-circuit overload limiting, no HART circuit

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

Terminal Type: Compression screw terminals for solid/stranded copper up to 14 AWG; each channel Ch+ / Loop– tied to shared global ground bus

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

Operating Ambient: 0℃ ~ +60℃ indoor cabinet; superior humidity, dust and mild corrosion tolerance vs -100/-125; not for continuous salt fog environments

Circuit Architecture Parameters

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

High-energy bidirectional TVS clamps positive/negative transient high voltage on each shared-ground input loop

Shared ground design: field-DCS ground potential offset will cause slight measurement drift (isolated FTA required for multi-ground plants)

Tight-tolerance input impedance guarantees stable full-span 4–20mA conversion precision

Reinforced current-limit resistors prevent transmitter burnout and IOP input damage under field short faults

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

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

Approximate Unit Weight: 0.360 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking heavy-duty flat ribbon cable connects directly to non-isolated non-HART AI IOP pins. Reinforced multi-point strain relief prevents pin deformation/fracture under long wiring harness tension.

Field Outer Terminals: 16 groups of Ch+ / Loop– terminals; all input loops reference one unified ground bus aligned with DCS control ground potential.

Signal Mechanism: Pure 4–20mA DC analog measurement signals; no HART coupling components integrated.

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

5. Core Functions

Common-ground low-cost signal acquisition: Designed for single-ground control rooms collecting standard non-HART transmitter signals.

Three-stage heavy EMI noise rejection: Suppresses strong electromagnetic interference from VFD banks and MCCs to stabilize readings and reduce signal fluctuation.

High-energy surge & short-circuit overload protection: Withstands lightning transients, switching surges and field shorts to protect delicate high-impedance IOP inputs and field transmitters.

Uniform measurement precision: Precision balanced passive components deliver identical conversion accuracy across all 16 channels, simplifying calibration work.

Strong inter-channel signal separation: Thick reinforced baffles greatly reduce analog crosstalk between adjacent measurement loops.

Redundant hot-swappable maintenance: Automatically follows primary/standby IOP switching logic; troubleshooting one channel does not affect the other 15 measurement points.

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 Measurement Loops

Safety loop pressure/differential pressure non-HART transmitters

High-volume process flow conventional transmitters

Large storage tank level measurement transmitters

Furnace/reactor temperature transmitters

Process water pH, conductivity analytical transmitters

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

7. Wiring Standards

Two-wire transmitter wiring: Transmitter positive → FTA Ch+, transmitter negative → FTA Loop– (shared ground bus); reversed polarity creates measurement offset and weakens surge protection performance.

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

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

8. Incompatible Hardware

All isolated AI/AO FTAs (51304644, 51304640, 51304728, 51304730), non-isolated HART AI (51304685), non-isolated AO FTAs (51304690, 51304718), DI/DO termination boards, TC/RTD dedicated FTAs, pulse counter and serial communication terminal assemblies cannot be paired with this non-isolated non-HART AI IOP card.