2. Model Definition

51304443: Base part number for 16-channel compact TC/RTD low-level analog input FTA, dedicated pairing with MC-AIL72 temperature IOP module

-100: Standard baseline PCB specification

Basic full-board conformal coating against normal humidity and dust accumulation

Standard bidirectional transient surge suppression and single-stage per-channel EMI filtering

Balanced ultra-low-noise differential trace layout optimized for weak millivolt thermocouple signals

Integrated per-channel standard precision Cold Junction Compensation (CJC) sensors

Matched IOP Hardware: MC-AIL72 (Compact UCN bus 16-point high-density low-level TC/RTD analog input IOP card)

Incompatible Hardware: HLAI high-level analog input FTA, HLAO analog output FTA, discrete DI/transistor/relay DO FTA, pulse counter FTA, serial communication FTAs

3. Technical Specifications

Channel Count: 16 independent low-level temperature input channels

Supported Field Sensors

Thermocouple (TC): Type J, K, T, E, R, S, B, N millivolt signals

RTD: Pt100, Pt1000 (2-wire & 3-wire resistance temperature detectors)

FTA Design: Passive termination structure; built-in per-channel CJC for TC cold junction correction; RTD excitation current supplied entirely by MC-AIL72 IOP

PCB Protection: Standard full conformal coating; flammability rating UL94 V0

Terminal Type: Compression screw terminals, compatible with solid/stranded copper wire up to 14 AWG

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

Operating Ambient: 0℃ ~ +60℃ (indoor control cabinet installation only)

Circuit Architecture

Ultra-low-noise balanced differential signal routing to minimize attenuation of tiny TC mV outputs

Single-stage per-channel low-pass EMI filtering for routine plant electrical noise rejection

Bidirectional transient overvoltage surge suppression diodes for basic wiring fault protection

Standard-precision integrated CJC temperature sensors for thermocouple offset correction

Matched impedance layout with basic channel partition barriers to reduce inter-channel signal crosstalk

Redundancy Compatibility: Fully supports primary/standby redundant MC-AIL72 IOP architecture; hot-swap IOP card replacement available

Approximate Unit Weight: 0.358 kg

4. Interface & Communication Configuration

Inner IOP Connection: Custom locking flat ribbon cable connector directly mates to MC-AIL72 IOP pin headers. Integrated cable strain relief prevents pin header bending or fracture caused by pulling tension from delicate TC/RTD extension wiring harnesses. No standalone communication chip; calibrated temperature PV values transmit to the DCS controller over the UCN control bus via the paired LLAI IOP module.

Field Outer Terminals: Distinct silkscreened terminal layouts differentiated for TC +/- wiring and 2/3-wire RTD hookups, with clear CJC reference marking. Basic physical channel separation reduces inter-channel signal interference.

Reference Power Supply: Cabinet 24VDC system power provides RTD excitation current through the MC-AIL72 IOP interface.

5. Core Functions

Cable Strain Relief: Protects fragile MC-AIL72 IOP pin headers from mechanical damage induced by long-term tension on thin temperature extension cables.

Standard Low-Noise Signal Preservation: Symmetric differential trace routing maintains integrity of weak thermocouple millivolt outputs to guarantee baseline temperature measurement precision.

Basic EMI Noise Filtering: Single-stage per-channel filters block routine interference from small VFDs and contactors, limiting minor temperature PV drift and fluctuation.

Basic Surge Clamping: Bidirectional diodes absorb low-magnitude voltage transients from minor wiring shorts and electromagnetic induction, safeguarding the MC-AIL72 low-level input front-end circuitry.

Standard Environmental Barrier: Basic conformal coating fully encapsulates PCB traces, solder pads and passive components to resist normal ambient humidity and dust buildup, enabling reliable 24/7 continuous operation in typical general-purpose industrial control cabinets.

Independent Single-Channel Maintenance: Separated terminal layout allows sensor replacement, loop resistance verification and field calibration for individual channels without disrupting measurement performance of the remaining 15 temperature monitoring circuits.

Redundancy Hot-Swap Capability: Standby MC-AIL72 IOP cards can be swapped online without interrupting critical furnace, reactor, boiler and heat exchanger temperature safety monitoring and closed-loop control logic.

6. Application Scenarios

Applicable Industries

Petrochemical complexes, chemical processing plants, thermal power stations, oil & gas refineries, pulp & paper mills, metallurgical facilities, water treatment stations, standard humidity pharmaceutical batch production lines.

Temperature Measurement Loops

Reactor vessel temperature, boiler/furnace tube temperature, distillation column tray temperature, extrusion mold temperature, heat exchanger inlet/outlet temperature, sterilizer batch temperature tracking.

Cabinet Deployment

Dedicated compact terminal base for 16-point low-level temperature analog input slots inside high-density space-saving DCS I/O control cabinets.

7. Operation, Wiring & Maintenance Instructions

Wiring Standards

Thermocouple circuits must use matching-type TC extension wire; strictly maintain polarity to avoid extra thermal offset measurement errors.

For 3-wire RTD installation, use equal-length, identical-gauge lead wires to balance line resistance for precise resistance measurement.

Deploy shielded twisted-pair cable for long-distance field runs; apply single-point shield grounding exclusively at the cabinet FTA side to prevent ground loop interference.

Route low-level temperature cables physically separate from high-current AC power cables to minimize electromagnetic coupling noise.

Spare Part Interchangeability

51304443-100 shares identical core low-noise temperature circuit topology with -125/-175/-200 upgraded variants for immediate emergency field substitution. The -100 baseline is cost-effective for non-corrosive, moderate humidity standard cabinet environments.

Standard Fault Troubleshooting Flow

Abnormal/unstable temperature PV → Retighten compression terminal screws → Verify TC/RTD sensor continuity and physical integrity → Inspect extension wire polarity & total loop resistance → Confirm ribbon cable is fully seated and locked into IOP header → Diagnose operational health of paired MC-AIL72 IOP card.