Core Configuration

Channels: 8 single-ended, electrically isolated digital outputs

Output Type: Active 24VDC (current injection / pull current selectable)

Load Capacity: 2A per channel, total 8A for the module

Architecture: TMR triple redundancy, 2oo3 voting, safety in case of faults

Isolation Voltage: 250VAC (channel ↔ backplane)

Diagnosis: Open circuit, short circuit, overload, inconsistent voting, load failure

Maintenance: Hot-swappable, online replacement without stopping operation

Status Indicators: LED per channel, power / operation / fault LED Electrical parameters

Output Voltage: 18–30VDC (rated 24VDC)

Conduction Resistance: ≤0.5Ω

Maximum Surge: 5A per channel (100ms)

Backplane Power Supply: 5VDC / 24VDC

Power Consumption: ≤10W

Operating Temperature: –40°C ~ +70°C

Humidity: 5–95% RH (no condensation)

Certifications: SIL3, CE, UL, CSA, ATEX Zone 2, TÜV

Size / Weight: 176×140×43mm / 1.2kg

Key Features

TMR Triple Redundancy: Three-channel independent output + voting, no single point failure, SIL3 safety level

Full Channel Isolation: 250VAC isolation, anti-earth potential difference, anti-strong electrical interference

High Current Drive: 2A per channel, can directly drive solenoid valves, relays, contactors

Complete Diagnosis: Real-time detection of open circuit / short circuit / overload, precise fault location

Wide Temperature + Hot Swap: –40°C ~ +70°C, online maintenance does not affect interlock

Fault Safety Design: System power loss / fault output in safe state (configurable)

Typical Applications

SIS/ESD Emergency Stop: SIL3 level valve shutdown, vent valve, emergency stop relay

F&G Fire Protection System: Drive sound and light alarm, foam / sprinkler solenoid valves

BMS Combustion Management: Igniter, fuel valve, purging valve control

Critical Unit Control: Compressor / turbine / pump interlock output, shutdown loop

Safety circuits requiring high reliability, isolation, and high current 24VDC output

Quick Overview of DO Modules in the Same Series

3708E: 8 channels, isolated, 24VDC/2A, TMR, SIL3 (commonly used)

3707E: 16 channels, non-isolated, 24VDC/0.5A, TMR

3706E: 32 channels, non-isolated, 24VDC/0.5A, TMR