Description
Product Introduction
True TMR Analog Input for Safety-Critical Measurements
The Triconex 3700 and 3700A are Triple Modular Redundant (TMR) analog input modules. Each module has three independent input channels per point. Every channel converts variable voltage signals to digital values. The system uses a mid-value selection algorithm for each scan. This method ensures correct data even with one faulty channel. Sensing prevents a single failure on one channel from affecting another. The module can operate properly with as many as two faulty channels.
Complete Ongoing Diagnostics Per Channel
Each channel runs continuous self-diagnostics. Any diagnostic failure activates the module Fault indicator. The chassis alarm signal then turns on. The Fault indicator points to a channel fault, not a module failure. You can quickly identify which channel needs attention.
Hot-Spare & Easy Replacement
The module supports hot-spare capability. You can replace a faulty module online without system shutdown. This keeps your safety system running at all times.
Technical Specifications (MECE Structured)
Brand & Model
– Manufacturer: Triconex – Model Numbers: 3700, 3700A – Type: TMR (Triple Modular Redundant) – Color Code: Yellow
Input Points & Signal Types
– Number of Input Points: 32, differential, DC coupled – Voltage Range (3700A only): 0 to 5V, +6% overrange – Current Range: 0 to 20 mA (uses 250 Ω shunt) – Isolated Points: No (common reference)
Measurement Accuracy & Resolution
– Resolution: 12 bits – Accuracy: < 0.15% of Full Scale Range (FSR) – Temperature Range for Accuracy: 0°C to 60°C
Input Impedance & Loading
– Input Resistance (load): 30 MΩ (DC), minimum – Power-Off Resistance: 30 KΩ (DC), typical
Rejection & Anti-Interference
– Common Mode Rejection: -80 dB (DC to 100 Hz), typical – Common Mode Range: -12V to +12V peak – Normal Mode Rejection at 8Hz: -3 dB – Normal Mode Rejection at 60Hz: -17 dB – Normal Mode Rejection at 120Hz: -23 dB – Leg-to-Leg Isolation: 200 KΩ, typical
Input Protection & Overrange
– Continuous Overrange Protection: 150 VDC / 115 VAC – Module survives accidental high voltage connection
Update Rate & Response
– Input Update Rate: 55 ms per scan
Environmental & Temperature Range
– Operating Temperature: 0°C to 60°C (32°F to 140°F) – Storage Temperature: -40°C to 85°C (-40°F to 185°F) – Humidity Tolerance: 5% to 95% non-condensing
Diagnostic Indicators
– Module Status LEDs: PASS, FAULT, ACTIVE – One status per module gives clear operational feedback
Installation & Mechanical
Mounting & Keying
– Mechanically keyed for correct insertion into a Tricon chassis – Requires a configured TMR backplane
Termination & Cabling
– Needs a separate External Termination Panel (ETP) – Cable interface connects directly to the Tricon backplane
Commissioning & Maintenance Convenience
Easy Commissioning
– Power up and watch the PASS LED – No special tools needed for basic verification
Maintenance Friendly
– Hot-spare allows online module replacement – Fault LED shows which channel has an issue – You do not need to guess or probe blindly
Compatibility
System Compatibility
– Fits all Tricon TMR chassis systems – Works with standard Tricon main processors – Uses same ETP family as other Tricon I/O
Partner Product References
– For similar safety I/O needs, see Modicon Quantum series from our partner.
Packaging List & Warranty
What’s in the Box
– 1 x Triconex 3700 or 3700A TMR Analog Input Module – Mechanical keying insert – No ETP or cable (order separately)
Warranty & Shipping
– 12 months warranty from shipment date – Covers manufacturing defects and component failures – Shipping carriers: FedEx, UPS, DHL – Tracking provided within 24 hours
Typical Applications
Where to Use the 3700/3700A
– Analog safety shutdown monitoring (pressure, temperature) – Turbine vibration and speed inputs – Reactor core analog signals – Continuous process variable monitoring in SIL-rated loops – Any 0-5V or 0-20mA transmitter feeding a safety system
FAQ (Frequently Asked Questions)
Q1: What is the difference between 3700 and 3700A?
The 3700A supports the 0-5V range with +6% overrange. The base 3700 has a different voltage range. Check your field transmitter.
Q2: Can I use this module for 4-20mA passive signals?
Yes. Add the external 250 Ω shunt resistor. The module then reads 0-20mA. Use a 250 Ω precision resistor.
Q3: What happens if two channels fail on the same input point?
The mid-value selection algorithm still picks the good remaining value. The system continues to operate correctly.
Q4: Does this module provide channel-to-channel isolation?
No. The inputs are not isolated from each other. Use external isolators if your field wiring needs full isolation.
Q5: How fast does the module update all 32 points?
The update rate is 55 ms for all points. This is fast enough for most safety logic scans.
Q6 (Experience-based): We see erratic readings near large VFDs. What can we do?
Check common mode rejection first. Install shielded twisted-pair wiring. Ground the shield only at the ETP end. The module has -80 dB CMR, but strong VFD noise needs good wiring practice.
Q7 (Selection Guide): Should I pick 3700A or a standard 12-bit analog card from another brand?
Pick 3700A if you need TMR voting and SIL-rated safety. Pick a standard card for non-safety monitoring only. The 3700A gives fault tolerance and online self-test.
Q8 (Selection Guide): We mix 0-5V and 0-20mA sensors. Do we need two modules?
Yes. Use one 3700A for voltage sensors. Use a separate module with external shunt for current sensors. Do not mix signal types on the same 32-point group.
Contact & Order Support
For urgent technical or sales inquiries:
+86 158 8020 0923 (WhatsApp)
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