Product Description

Overview

The Triconex 3805E Analog Output (AO) Module is engineered for Tricon™ Triple Modular Redundancy (TMR) systems, providing precise and reliable analog outputs for safety-critical control loops. It drives final control elements such as valves, actuators, and motor controllers, ensuring robust performance even under fault conditions.

Key Features

Triple Modular Redundancy and Voting
The 3805E incorporates a patented TMR output voting mechanism. Each of the three redundant legs receives signals from the Main Processors, converts them to analog, and votes on the correct output. If one leg fails, the remaining two maintain accurate control, preventing hazardous failures or unnecessary trips.

High-Precision Output

• Output Range: Standard 4–20 mA, with over-range capability up to 22 mA

• Resolution: 12-bit for fine modulation of control elements

• Accuracy: Better than 0.25% of full-scale across operating temperatures from 0° to 60°C (32°–140°F)

Advanced Diagnostics and Loop Monitoring

• Continuous current loop monitoring with real-time comparison to commanded values

• Detection of open circuits, short circuits, and stuck-at faults

• Built-in diagnostics to verify actuator and valve responsiveness

Maintenance and Reliability

• Hot-Swappable: Replace the module without shutting down the process

• Status Indicators: PASS, FAULT, ACTIVE, LOAD, PWR1, and PWR2 LEDs

• Galvanic Isolation: Protects the internal system from external electrical surges

• SIL 3 Certified: Fully compliant with IEC 61508 for high-integrity applications

Technical Specifications

Applications

• Modulating Valves: Precise flow and pressure control in critical safety zones

• Turbine Speed Control: Interfaces with electronic governors for high-speed machinery

• Damper Actuators: Burner Management System (BMS) control for air/fuel ratio

• Variable Speed Drives (VSD): Critical motor setpoint control

Note: Optimal reliability is achieved when used with a compatible External Termination Panel (ETP) to supply redundant field power to output loops.

FAQ

Q: Can the 3805E be replaced without shutting down the system?
A: Yes, it supports hot-swap operation while maintaining control through active modules.

Q: What is the output resolution of this module?
A: The module provides 12-bit resolution, allowing smooth analog control.

Q: Is the 3805E suitable for SIL 3 applications?
A: Yes, it is IEC 61508 SIL 3 certified for high-integrity safety systems.