1. Introduction

• Function: 40‑channel analog input (mA / VDC)

• Architecture: Fully triplicated TMR (3‑2‑0)

• Safety: IEC 61508 SIL 3

• Inputs: 0–22 mA / 0–6 VDC (per channel configurable)

• Resolution: 3.9 µA (1/256 mA)

• Accuracy: ±1% full scale (safety accuracy)

• Isolation: 2500 VDC optical isolation

• SOE: 1 ms resolution

• Hot‑swap: Supported

• Operating Temp: 0 °C to +60 °C (standard)

2. Product Overview

• 40 channels of isolated analog input (0–22 mA / 0–6 VDC)

• Triple Modular Redundancy (TMR) for fault tolerance

• Per‑channel 1oo2D voting and diagnostics

• High‑resolution sigma‑delta ADCs

• 2500 VDC optical isolation (field‑to‑system)

• Open/short‑circuit detection per channel

• Over‑range / under‑range fault detection

• 1 ms resolution SOE logging

• Front‑panel LED status indicators

• Hot‑swap capable

• Compatible with T8100 / T8400 chassis

3. Specifications

3.1 Mechanical

• Form Factor: T8000 chassis module, 31 mm wide, 6U height

• Dimensions (H × W × D): 266 mm × 31 mm × 303 mm

• Weight: 1.15 kg

• Mounting: T8100 / T8400 chassis slots 1–16

• Terminals: Front‑panel terminal blocks (40 channels)

3.2 Electrical

• System Supply: 20–32 VDC (nominal 24 VDC)

• Power Consumption: 15–18 W

• Input Ranges (per channel configurable):

  • Current: 0–22 mA

  • Voltage: 0–6 VDC

• Resolution: 3.9 µA (current), 23.4 µV (voltage)

• Safety Accuracy: ±1% full scale

• Calibration Accuracy: 0.03%

• Isolation: 2500 VDC optical barrier

• Channel Crosstalk: –40 to –60 dB

• Update Time: 0.5 ms per channel

3.3 Functional

• Redundancy: TMR (three independent measurement paths)

• Voting: 1oo2D per channel

• Diagnostics:

  • Open‑circuit detection

  • Short‑circuit detection

  • Over‑/under‑range detection

  • On‑board BIST (every 2 minutes)

• SOE Resolution: 1 ms

• Response Time: ≤ 2 ms

• Data Integrity: BER < 10⁻¹²

3.4 Environmental

• Operating Temperature: 0 °C to +60 °C

• Storage Temperature: –25 °C to +70 °C

• Humidity: 10–95 % RH, non‑condensing

• Vibration: IEC 60068‑2‑6 (1 g, 10–150 Hz)

• Shock: IEC 60068‑2‑27 (15 g, 11 ms)

3.5 Safety & Certification

• Safety Standard: IEC 61508 SIL 3

• Approvals: CE, UL, CSA, ATEX, IECEx

• Fault Tolerance: TMR (3‑2‑0)

• PFHd: < 1.0 × 10⁻⁹ / hour (SIL 3)

4. Front Panel Indicators

• PWR (Green): ON = module power healthy

• RUN (Green): ON = active; FLASHING = BIST/initialization

• FAULT (Red): ON = critical fault; FLASHING = minor fault

• COM (Green): FLASHING = backplane communication active

• CH1–CH40 LEDs: Reflect input status / fault per channel

5. Installation

• Chassis: Insert into any vacant slot in T8100 / T8400 chassis

• Hot‑Swap: Supported; no system shutdown required

• Front‑Panel Screws: Torque 0.8–1.0 Nm

6. Wiring

• Signal Types: 4–20 mA / 0–20 mA / 0–6 VDC

• Field Connection:

  • mA: Transmitter + → channel +; transmitter – → channel –

  • VDC: Signal + → channel +; signal – → channel –

• Wire Gauge: 16–22 AWG stranded

• Terminal Torque: 0.5–0.6 Nm

• Line Monitoring: External resistor for open‑circuit detection

7. Operation

• Power‑Up: PWR ON; RUN flashes during BIST (5–10 s)

• Normal: PWR/RUN steady green; FAULT OFF; COM flashing

• Faults:

  • FAULT ON: TMR mismatch, short circuit, overrange

  • FAULT FLASHING: Single‑path fault, minor mismatch

• SOE: All analog threshold crossings time‑stamped at 1 ms

8. Ordering Information

• T8431: Standard 40‑ch TMR analog input (0–60 °C)

• T8431C: Conformal coated, –40 °C to +70 °C (harsh env.)

• TC‑T8431: Terminal cable kit

• T8100 / T8400: Trusted chassis