TRICONEX 2351

Analog Input Module (8‑Channel, TMR, 4–20 mA)

Official Specification & User Manual (English)

1. General Description

2. Part Number & Type

• Model: 2351 (also AI2351)

• Type: Analog Input Module (AI), TMR

• Series: Trident (Triconex / Schneider Electric)

• Safety Level: SIL 3 (IEC 61508)

• Approvals: TÜV Rheinland, FM, CSA

3. Key Features

• 8 Isolated Analog Input Channels

  Accepts 4–20 mA current signals (field transmitters).

• Triple Modular Redundancy (TMR)

  Three independent measurement circuits per channel; majority‑voted results eliminate single‑point faults.

• High Accuracy & Resolution

  16‑bit resolution, ±0.25% FS accuracy, 2500 V RMS galvanic isolation.

• Configurable Ranges & Filtering

  4–20 mA (default); configurable damping/filter time (0–10 s).

• Hot‑Swappable

  Replace module online without system shutdown.

• Comprehensive Diagnostics

  Open/short‑circuit detection, over/under‑range alarm, and SOE time stamping (≤ 40 ms).

4. Technical Specifications

4.1 Input Channels

• Number: 8 channels, isolated per channel

• Signal Type: 4–20 mA DC (current loop)

• Resolution: 16‑bit

• Accuracy: ±0.25% FS (25°C)

• Isolation: 2500 V RMS channel‑to‑backplane

• Input Impedance: 250 Ω

4.2 Safety & Redundancy

• Architecture: Triple Modular Redundant (TMR), 2oo3 voting

• Safety Integrity Level: SIL 3

• Fault Coverage: > 99%

• System Availability: 99.999%

4.3 Environmental

• Operating Temperature: 0°C to +60°C

• Storage Temperature: −40°C to +85°C

• Humidity: 5%–95% non‑condensing

• Vibration: 5–200 Hz, 1g

• Protection Class: IP20 (module)

4.4 Power

• Backplane Power: 5 VDC / 1.2 A (from Trident chassis)

• Field Power: External 24 VDC (for 4–20 mA loops, user‑supplied)

4.5 Physical

• Dimensions: 133 mm × 114 mm × 32 mm (5.25” × 4.50” × 1.25”)

• Weight: ~0.3 kg

• Mounting: Trident baseplate, 19” rack compatible

5. Functional Overview

• Analog Signal Acquisition

  Reads 4–20 mA signals from pressure, temperature, level, and flow transmitters.

• Triple Voting & Conversion

  Three independent A/D converters per channel; results are majority‑voted to ensure data integrity.

• Diagnostics & Alarms

  Detects open circuit, short circuit, overrange (>20 mA), underrange (<4 mA); reports to TriStation.

• SOE & Data Logging

  Time‑stamps process value changes and fault events for safety analysis and compliance.

6. LED Indicators

• PWR (Green): Module power OK

• RUN (Green): Module active, communicating

• FAULT (Red): Channel or module fault

• CH 1–8 (Yellow): Channel active / fault

7. Installation & Configuration

1. Insert 2351 into an empty Trident baseplate slot.

2. Connect field 4–20 mA transmitters to the 8‑channel terminal block.

3. Apply external 24 VDC field power to current loops.

4. Use TriStation 1131 to:

   • Enable/disable channels

   • Set filter/damping time

   • Configure fault thresholds (e.g., <3.8 mA = underrange)

5. Verify LED status: PWR + RUN green, no FAULT red.

8. Typical Applications

• Emergency Shutdown (ESD) systems

• Burner Management Systems (BMS)

• High‑Integrity Pressure Protection (HIPPS)

• Process safety interlocks (pressure, temperature, level)

• Fire & gas detection systems

9. Maintenance

• Hot‑swap faulty 2351 without shutdown.

• Inspect field wiring, terminals, and 24 VDC loop power periodically.

• Review SOE and fault logs via TriStation.

• Update firmware as needed.

10. Ordering Information

• Model: 2351 (AI2351)

• Description: Triconex Trident 8‑Channel TMR Analog Input Module (4–20 mA)

• Compatible with: Trident Chassis, 2101/3700A MP Modules, TriStation 1131