8-Channel Pulse Input (PI) Module for Tricon TMR Safety Systems

The TRICONEX 3511 is an 8-channel pulse input (PI) module designed for the Triconex Tricon Triple Modular Redundant (TMR) Safety Instrumented System (SIS). It provides high-precision frequency, speed, and pulse counting measurement in mission-critical applications.

With Triple Modular Redundancy (TMR) architecture, 16-bit resolution, hot-swappable design, and SIL 3 certification, the 3511 module is widely used in high-risk industries requiring continuous operation and maximum safety integrity.

1. Core Positioning & System Adaptation

Model: TRICONEX 3511

Module Type: Pulse Input (PI) Module

System Compatibility: Triconex Tricon TMR Fault-Tolerant Control System

Safety Integrity Level: SIL 3 (IEC 61508 / IEC 61784-3 compliant)

Lifecycle Status: Active / Mainstream production

Typical Functions:

Speed monitoring

Flow pulse measurement

Position counting

Overspeed and equipment protection (ESD)

2. Key Technical Specifications
2.1 Input Characteristics

Number of Channels: 8 independent differential pulse inputs (non-common ground)

Frequency Range:

Standard: 20 Hz to 20 kHz

Alternative specification: 1 Hz to 10 kHz (application dependent)

Resolution: 16-bit

Measurement Accuracy: ±0.01% (1000 Hz to 20,000 Hz range)

Pulse Width Resolution: 100 μs

Input Type:

AC-coupled

Balanced differential

Adaptive to magnetic speed sensors

Input Impedance: Typical 20 kΩ

Common Mode Range: −100 V to +100 V (peak-to-peak)

Overvoltage Protection: ±150 V DC (continuous)

2.2 Architecture & Reliability

Redundancy Architecture:

Triple Modular Redundancy (TMR)

2-out-of-3 (2oo3) voting mechanism

Single point failures do not affect system operation

Hot Swap Capability:

Supported

Online replacement without system shutdown

Update Rate: Typical 25 ms

Diagnostics:

Full per-channel diagnostics

Module status indicators (PASS / FAULT / ACTIVE)

Channel-level fault detection

2.3 Electrical & Mechanical Specifications

Supply Voltage: 24 V DC (operating range 8–30 V DC)

Operating Temperature: −40 °C to +70 °C

Installation: Standard Tricon rack mounting

Weight: Approx. 3.03 kg

3. Typical Application Scenarios
Rotating Equipment Monitoring

Steam turbines

Compressors

Pumps

Motors

Acquisition of speed and vibration pulse signals

Flow Measurement

High-precision pulse counting from:

Turbine flowmeters

Vortex flowmeters

Positive displacement meters

Safety Interlock & ESD Applications

Overspeed protection

Zero-speed detection

Position counting for trip logic

Emergency shutdown triggering

High-Risk Industry SIS Systems

Deployed in Safety Instrumented Systems (SIS) across:

Oil & Gas

Petrochemical

Power generation

Metallurgy

Heavy industrial processes

TRICONEX 3511｜Pulse Input Module｜