2. Model Definition

51304748: Base model for 16-channel galvanically isolated non-HART analog input FTA

-125: Mild reinforced PCB protection grade

Medium-upgraded full-board conformal coating with improved resistance to humidity, dust and weak corrosive vapors versus -100 baseline

Moderate high-energy bidirectional TVS transient, ESD and line fault surge protection with independent per-channel isolation

Dual-stage cascaded RC differential EMI filter precisely tuned to suppress medium-level industrial electromagnetic interference

Independent reinforced galvanic isolation barrier for each channel; no electrical connection between field loop, DCS ground and adjacent channels

Reinforced loop short-circuit current limiting resistors for isolated loop overload protection of transmitters and IOP input circuits

Precision matched isolated input impedance resistors for uniform 4–20mA measurement accuracy across all channels

Thickened plastic channel baffles to reduce inter-channel analog signal crosstalk & leakage

3. Technical Specifications

Channel Count: 16 fully independent input loops, complete galvanic isolation per channel

Compatible Field Devices

Two-wire non-HART 4–20mA transmitters: pressure, differential pressure, flow, level, temperature, pH, dissolved oxygen, conductivity conventional transmitters

FTA Structure: Passive isolated termination board with no internal power supply; integrated dual-stage differential filtering, medium-energy isolated surge protection and short-circuit current limiting, no HART circuit

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 isolated Ch+ / Loop– field terminals electrically separated from DCS ground and other loops

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

Operating Ambient: 0℃ ~ +60℃ indoor control cabinet; wider tolerance for humidity, dust and weak corrosion compared to -100; not rated for continuous salt fog or strong corrosive chemical fume environments

Circuit Architecture Parameters

Dual-stage low-pass differential filtering suppresses medium-level EMI from medium VFD and MCC loads

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

Per-channel galvanic isolation fully eliminates measurement drift caused by field-to-DCS ground potential differences, works reliably for multi-ground and single-ground plants

Tight-tolerance isolated input impedance ensures consistent 4–20mA conversion accuracy across full signal range

Matched current-limit resistors prevent transmitter burnout and IOP input damage during field short faults

Thickened baffles minimize inter-channel analog bleed and cross-measurement interference

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

Approximate Unit Weight: 0.359 kg

4. Interface & Communication Configuration

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

Field Outer Terminals: 16 groups of independent isolated Ch+ / Loop– terminals; each input loop is electrically separated from DCS control ground and neighboring channels.

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

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

5. Core Functions

Full per-channel galvanic isolation: Permanently eliminates ground loop interference, stable operation for both complex multi-ground industrial plants and standard single-ground layouts.

Dual-stage medium EMI noise suppression: Reduces moderate electromagnetic interference from VFD and MCC equipment to stabilize measurement readings and cut signal fluctuation.

Medium-strength surge & short-circuit protection: Absorbs moderate wiring transients and short-circuit overload to protect sensitive IOP high-impedance input circuits and field transmitters.

Uniform measurement accuracy: Precision balanced passive components deliver identical 4–20mA conversion performance across all 16 channels to simplify calibration work.

Balanced inter-channel signal isolation: Thickened partition baffles restrain analog crosstalk between adjacent measurement loops.

Redundant hot-swappable operation: Automatically synchronizes with primary/standby IOP switching logic; single-channel disconnection and troubleshooting do not disrupt operation of the remaining 15 measurement loops.

6. Application Scenarios

Applicable Industries

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

Typical Measurement Loops

General process pressure/differential pressure conventional transmitters

Utility flow rate non-HART transmitters

Atmospheric tank level measurement transmitters

Standard temperature transmitters

Clean water pH, conductivity analytical transmitters

Fit for multi-ground and single-ground plant layouts, medium-noise VFD process zones, cabinets with mild elevated humidity and moderate dust accumulation, atmospheres with low-concentration weak acid/alkaline volatile vapors. Not applicable for continuous salt fog or heavy corrosive chemical workshop cabinets.

7. Wiring Standards

Two-wire transmitter wiring: Transmitter positive → isolated FTA Ch+, transmitter negative → FTA Loop–; reversed polarity causes measurement offset and reduces surge protection effectiveness.

Cable specification: Shielded twisted-pair instrument cable for all field wiring runs; cable shield grounded solely at DCS cabinet FTA side with field transmitter end ungrounded to suppress residual noise.

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

8. Incompatible Hardware

All non-isolated AI/AO FTAs (51304736, 51304685, 51304672, 51304690, 51304718), isolated HART AI (51304644), isolated HART AO (51304728), isolated non-HART AO (51304730), discrete DI/DO termination boards, TC/RTD dedicated FTAs, pulse counter termination blocks and serial communication terminal assemblies cannot be paired with this isolated non-HART AI IOP card.