TRICONEX 3721

Description

• Channels:​ 32 differential channels, independently isolated per channel
• Voltage Range:​ 0–5 VDC or -5 to +5 VDC (±6%), single/dual polarity software-selectable
• Current Range:​ 0–20 mA (requires external 250 Ω shunt resistor); 4-20 mA compatible
• Update Rate:​ 10 ms
• Resolution:​ 12-bit or 14-bit (programmable)
• Accuracy:​ <0.15% FSR (0–60 °C)
• Common Mode Rejection Ratio (CMRR):​ -85 dB (DC–100 Hz)
• Overvoltage Protection:​ 150 VDC / 115 VAC continuous
• Branch Isolation:​ 420 kΩ typical
• Channel Off-State Impedance:​ 140 kΩ typical
• Operating Temperature:​ -40 °C to +70 °C
• Storage Temperature:​ -40 °C to +85 °C
• Weight:​ 1.36 kg net
• Safety Certification:​ TÜV certified, IEC 61508 SIL 3 / AK 7
• System Requirement:​ Tricon system v10.2 or higher firmware

• Triple modular redundant architecture with 2oo3 voting ensures signal integrity
• Differential input design with -85 dB CMRR eliminates ground loop and EMI interference
• Programmable 12-bit or 14-bit resolution balances speed and precision
• Continuous overvoltage protection up to 150 VDC safeguards module and connected sensors
• Front panel PASS, FAULT, ACTIVE, and FIELD LEDs provide instant diagnostic feedback
• Hot-swappable with on-board self-test and per-channel diagnostics
• Automatic fault channel exclusion maintains process availability

• Safety-critical pressure, flow, temperature, and level measurement
• Anti-surge control and compressor protection
• Precision reactor and vessel monitoring
• Emergency shutdown system analog signal acquisition
• Fire & Gas system sensor interfaces
• Pharmaceutical, petrochemical, oil & gas, and power generation applications

• Install in a Tricon v10.2 or higher rack system
• For 4-20 mA transmitters, install a 250 Ω precision shunt resistor externally to convert to 1-5 V
• Ensure proper grounding to leverage the -85 dB common-mode rejection
• Mount in a control cabinet maintaining -40 °C to +70 °C ambient
• Verify mechanical keying matches the designated I/O slot

• The module does NOT provide intrinsic sensor excitation — external power must be supplied
• 3721 (analog input) is NOT interchangeable with 3720 (digital input) — hardware and firmware are incompatible
• For 0-20 mA signals, the external 250 Ω resistor converts to a 0-5 V input range
• Monitor the FIELD LED to confirm proper field-side power and signal presence
• Do not confuse with 3704E, which is a high-speed analog input module with different sampling rates and range configuration