Model Interpretation

• 3502E: TMR Digital Input Module, 48V AC/DC, with Self‑Test, SIL3

• P/N: 3502E (base; “TMR” is its core architecture, not a separate suffix)

• Compatibility: Tricon v9–v12 chassis (8110/8111/8112/8115/8116); hot‑swappable

• Key Upgrade: 32 channels (8 groups × 4 commoned), 35–95V AC/DC, self‑test for de‑energize‑to‑trip circuits

Technical Parameters

Electrical & Input

• Input Type: Dry/wet contact, 48V AC/DC nominal (35–95V AC/DC)

• Channels: 32, commoned in 8 groups (4 channels per group)

• Input Current: 6–9mA (on‑state)

• Backplane Power: 24VDC (20.4–28.8VDC), ~150mA

• Isolation: 1,500VDC channel‑to‑backplane galvanic isolation

• Frequency: DC or 47–63Hz AC

Redundancy & Safety

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

• Safety Certification: IEC 61508 SIL3, TÜV, UL, CE, ATEX, FM

• Diagnostics: >99.9% fault coverage; self‑test for off‑state detection; SOE (≤40ms resolution)

• MTBF: >150,000 hours

Mechanical

• Form Factor: 3U, 19” rack, 1 slot

• Dimensions (W×H×D): 114 × 30 × 185 mm

• Weight: ~0.9 kg (2.0 lbs)

• Mounting: Plug‑in backplane, hot‑swappable

Environmental

• Operating Temp: −40°C to +70°C

• Storage Temp: −40°C to +85°C

• Humidity: 5%–95% RH, non‑condensing

Diagnostics & Indicators

• LEDs: PASS, FAULT, ACTIVE, TMR, ALARM

• Fault Detection: Open/short circuit, channel mismatch, TMR deviation, self‑test fault

Core Functions

1. 48V AC/DC Safety Input for SIS

   Accepts 35–95V AC/DC field signals (ESD pushbuttons, F&G detectors, interlock switches); 32 commoned channels (8 groups) reduce wiring complexity。

2. TMR Fault‑Tolerant Voting

   Three independent input circuits per signal; 2oo3 voting eliminates single‑point failures—critical for SIL3 ESD/F&G/BMS loops。

3. Self‑Test for De‑Energize‑to‑Trip

   Unique self‑test verifies detection of off‑state transitions, ensuring safety for “de‑energize‑to‑trip” systems (standard in most SIS)。

4. Hot‑Swap & Online Maintenance

   Replace module without system shutdown; supports online diagnostics and SOE logging for compliance。

5. High‑Noise Immunity

   Opto‑isolation + TMR design rejects ground loops and electrical noise—ideal for harsh oil/gas/chemical environments。

Applications

• Oil & Gas: Offshore ESD/F&G systems; 48V AC/DC safety switches

• Chemical/Refining: Process interlocks; medium‑voltage discrete safety signals

• Power Generation: Turbine ESD; boiler safety interlocks

• SIS Retrofits: Upgrade legacy Tricon v9–v12 systems with SIL3 48V DI