Triconex 3664 / 3674 Dual Digital Output Module

The Triconex 3664 Dual Digital Output Module is designed to support safety-critical control programs with robust diagnostics and redundancy mechanisms while maintaining cost efficiency. Below is a detailed overview of its specifications and operational features.

Key Features

Dual Redundancy Design:
- Implements 2-out-of-3 voting on each switch for safe and reliable output generation.
- Optimized for safety-critical applications where cost efficiency is prioritized over maximum availability.
Voltage Loopback Circuit:
- Verifies the operation of output switches, ensuring functionality even without load presence.
- Triggers the LOAD/FUSE alarm when field voltage mismatches the commanded output state.
Comprehensive Diagnostics:
- Continuously monitors each channel and circuit.
- Activates the Fault Indicator and chassis alarm signal upon diagnostic failure.
Hot-Spare Capability:
- Allows online replacement of faulty modules without system downtime.
Mechanical Keying:
- Prevents improper installation into the chassis.

Specifications

Feature	Details
Model Numbers	3664 / 3674
Nominal Voltage	24 VDC
Voltage Range	16-30 VDC
Maximum Voltage	36 VDC
Voltage Drop	<1.5 VDC (typical)
Output Signals	32, commoned
Current Ratings	2A per point (max), 10A surge for 10 ms
Load Leakage	2 mA (max)
Power Module Load	<10 watts
Point Isolation	Minimum 1500 VDC
Diagnostic Indicators	ON/OFF state, Module Status, Field Alarm, Load/Fuse, and Point-specific Fault Alarms
Fuses	Self-protecting (no external fuses required)
Color Code	Dark Blue

Diagnostic Indicators

ON or OFF State: Indicates the status of each point.
Module Status: Displays PASS, FAULT, and ACTIVE conditions.
Field Alarm: Alerts users to discrepancies like stuck-ON or stuck-OFF faults.

Fault Handling:

Stuck-ON Faults:
- 3664: Affected point remains ON while others retain their commanded states.
- 3674: Affected point remains ON while others are de-energized.
Stuck-OFF Faults:
- Affected point remains OFF, but other points maintain their commanded states.

Environmental Specifications

Parameter	Details
Shock Resistance	10G, ½-sinewave for 11 ms
Vibration Resistance	1 mm peak-to-peak from 5–16 Hz, 0.5G from 16–150 Hz
Operating Temperature	0°C to 60°C (32°F to 140°F)
Airborne Contaminants	Meets ISA-S71.04-1985 Airborne Contaminants Class G3 standards

Field Termination and Power Considerations

Requires a separate External Termination Panel (ETP) for cable interface with the Tricon backplane.
Designed for sourcing current to field devices, necessitating field power wiring to each output point.

The Triconex 3664 Dual Digital Output Module provides a cost-efficient yet reliable solution for safety-critical applications. Its dual redundancy, advanced diagnostics, and hot-spare capability enhance system safety and reduce downtime during maintenance.