Triconex 3381 pulse input module

Core functions and features

High-precision pulse counting

Supports pulse frequency input up to 10kHz, meeting the monitoring requirements of high-speed rotating equipment such as turbines and compressors.

16-bit resolution ensures precise detection of minute flow or speed changes.

Each channel is independently configured with a filtering time (0.1ms to 100ms), which has strong anti-interference ability.

Triple redundancy architecture

By adopting TMR technology, three independent channels process the same signal in parallel, and the data reliability is ensured through the 2003 voting mechanism.

A single-channel failure does not affect the system operation and simultaneously triggers a diagnostic alarm.

Wide-range input compatibility

Supports multiple signal types: dry contacts, wet contacts, NAMUR sensors, TTL/CMOS levels.

Input voltage range: 5-30VDC (configurable by the user), suitable for different industrial equipment.

Advanced diagnostic function

Real-time monitoring of channel status, supporting open circuit/short circuit detection and signal loss alarm.

Built-in watchdog timer to ensure the normal operation of the processor.

Security certification

It complies with the safety standards of IEC 61508 SIL3 and ISA 84.00.01 and is suitable for safety-critical applications.

It has passed the ATEX/IECEx explosion-proof certification and can be used in hazardous areas.

Technical parameters

Number of channels: 8 or 16 channels (depending on the specific model)

Input type: Digital pulse (dry contact/Wet contact/level)

Frequency range: 0.1Hz to 10kHz (configurable)

Resolution: 16 bits

Response time ≤10ms (typical value)

Isolation voltage: 2500VDC (isolation between channels and from ground)

Operating temperature: -40°C to +75°C

Power consumption <5W (typical value)

The communication interface supports industrial protocols such as Modbus and Profibus

Working principle

Signal acquisition

The external pulse signal enters the module through the isolation circuit. Each channel is independently sampled and converted into a digital signal.

Triplet processing

Three processors process the same pulse signal in parallel and calculate parameters such as pulse frequency and cumulative value.

Voting and Output

The calculation results of the three channels are compared through the 2003 voting mechanism, and the consistent result is sent as a valid output to the control system.

Fault detection

The processing results of the three channels are compared in real time. If the deviation exceeds the threshold, a fault alarm is triggered and an abnormal channel is marked.

Typical application scenarios

Flow measurement and control

Monitor the pulse output of turbine flowmeters and electromagnetic flowmeters for precise measurement of fluid flow.

Speed and position monitoring

Measure the rotational speed of rotating equipment such as motors, pumps and fans to achieve closed-loop speed control.

Safety interlock system

In the emergency shutdown system (ESD), as a key sensor input, it ensures the safe shutdown of the equipment in abnormal situations.

Energy management

Collect pulse data from electricity meters and steam meters to achieve real-time monitoring and analysis of energy consumption.

Configuration and Integration

Software Tools: Configure parameters such as sampling rate, filtering time, and range through TriStation 1131 or Tricon Configuration Tools.

Redundant configuration: Supports the formation of a complete redundant system with other Triconex modules (such as 3009 processor, 3604 output module).

Hot-swappable design: Supports online module replacement without downtime, reducing maintenance time.