Product Description

Overview

The Triconex 3805E is a high-integrity Analog Output (AO) module engineered for critical Safety Instrumented Systems (SIS). Designed for the Tricon Triple Modular Redundant (TMR) architecture, it provides reliable control for field devices including control valves, actuators, and variable-speed drives. Its TMR design ensures uninterrupted output even in the event of a single internal fault.

Architecture and Design

3805E features three independent processing legs, each executing output commands simultaneously. A hardware voting mechanism determines the final output, delivering unmatched safety and reliability. The module is pea green, conforming to standard Triconex AO color coding, and supports hot-swappable installation in redundant system configurations.

Performance Highlights

High Availability and Fault Tolerance

• Triple Modular Redundant architecture for uninterrupted operation

• Rapid leg failover: <10 ms typical, preventing output disturbance

• Hot-swappable with online replacement capability in redundant configurations

Precision Control

• 8-point output with commoned return, DC coupled

• 12-bit resolution for precise current control

• Output accuracy better than 0.25% Full Scale Range (0–21.2 mA) across 0°C to 60°C

• Supports +6% over-range (up to 21.2 mA)

Diagnostics and Monitoring

• Continuous loopback monitoring of actual output versus command

• Detection of open circuits and loss of field power

• Front panel LEDs: PASS, FAULT, ACTIVE, LOAD, PWR1, PWR2 for quick troubleshooting

System Protection

• Over-voltage protection up to +42.5 VDC continuous

• Galvanic isolation to prevent ground loops and protect the main controller

Technical Specifications

Application Notes

The 3805E is ideal for general-purpose 4–20 mA loops in process control systems. For applications with highly inductive loads such as large solenoid valves, the 3805H variant is recommended due to enhanced handling of inductive spikes.

FAQ

Q: Can the 3805E be replaced without shutting down the system?
A: Yes, it supports hot-swappable installation in a redundant configuration.

Q: What is the maximum output voltage the module can tolerate?
A: It provides over-voltage protection up to +42.5 VDC continuous.

Q: How precise is the analog output?
A: The module achieves <0.25% FSR accuracy over 0–21.2 mA, even across the full operating temperature range.