I. Core Positioning

HCU3700 is a TMR analog input module with HART functionality, not an FTA terminal board, directly plugged into the Tricon rack, and used in conjunction with FTA-554; it supports 4–20mA + HART intelligent transmitters, capable of simultaneously collecting analog and digital HART data. It is the preferred choice for SIS system intelligent instrument integration.

II. Specification Parameters (Official Standard Version)

1. Channels and Signals

Channels: 8 isolated analog input (AI), TMR triple redundancy

Signals: 4–20mA (with HART), 0–20mA, 0–5V, 0–10V, ±10V

Resolution: 16 bits

Accuracy: ±0.05% FS (analog); HART data 100% transparent

Input Impedance: Current 250Ω; Voltage ≥1MΩ

Isolation: Channel-to-channel 1500VAC, channel-to-backplane 1500VAC

HART: Independent HART modulation per channel, supports HART 5/7, can read/write instrument parameters, diagnostics, range, TAG

2. Electrical and Redundancy

Power Supply: 24VDC (±10%), backplane power supply

Redundancy: TMR triple redundancy architecture, three CPU voting, single channel failure does not affect the system

Diagnosis: Open circuit, short circuit, overrange, HART communication failure, fuse melting

Power Consumption: Approximately 8W

3. Mechanical and Environment

Size: 225 × 112 × 40mm (standard Tricon I/O size)

Weight: Approximately 1.2kg

Installation: Tricon standard I/O rack slot, hot-swappable

Temperature: -40℃ ~ +70℃ (wide temperature range)

Certification: CE, UL, CSA, TÜV SIL3, ATEX (available in explosion-proof areas)

4. Panel and Interface

Inner Side: Backplane bus, TMR triple communication

Outer Side: D-SUB 37-pin, connects FTA-554 terminal board

Indicators:

PWR (green): Module power supply normal

RUN (green): Module running normally

CH1–CH8 (yellow): Channel signal normal

FAULT (red): Module/Channel failure

HART (blue): HART communication active

III. Required Terminal Board

FTA-554: 8-channel isolated AI terminal board, with fuses, surge protection, LED diagnostics, dedicated for 4–20mA + HART wiring on-site.

IV. Typical Applications

SIS/ESD: Intelligent pressure / flow / level / temperature transmitters (HART) signal acquisition

Process: HART feedback for control valves, remote diagnostics and parameter modification of instruments

Safety: SIL3 circuit, open circuit / short circuit / overrange / HART communication failure diagnosis

Intelligent Factory: HART instrument data upload to DCS / upper computer, achieving instrument health management, predictive maintenance

V. Model Distinction (To Avoid Confusion)

HCU3700: 8-channel HART AI, TMR, isolated, SIL3 (mainstream)

HCU3703E: Same as HCU3700, enhanced HART, supports HART 7.1, multi-variable (PV/SV/TV/QV)

AI3401: 8-channel ordinary AI (without HART), isolated, SIL3

AI6503: 8-channel high-precision AI (without HART), wide temperature range, strong anti-interference