Triconex 3401 DO 3401 Digital Output Module

Tech Information

Points 16, commoned

Nominal output voltage 24 VDC

Specified operational voltage range 15 to 30 VDC

Absolute maximum output voltage 33 VDC

Absolute maximum reverse input

Voltage: – 0.6 VDC

Output current: Switching <4.8 A, self-limiting; 3.0 A, typical

Degraded mode > 0.7 A, self-limiting; 1.5 A, typical

Field alarms: Loss of field power, output point shorted On or Off

Loop-back thresholds 0–5 VDC = Off region

6–14 VDC = transition region

15–30 VDC = On region

Leakage to load (Off state) <1 mA

Diagnostic glitch duration <2 ms, maximum 500 ?s, typical

Diagnostic fault coverage

Maximum toggle rate: >20 ms

Minimum toggle rate: Not applicable

On state voltage drop <1.0 VDC @ 1.5 A

Loop-back scan time <1.0 ms for all 16 points

Functional earth to protective earth isolation: 500 VDC, minimum

Functional earth to functional earth (logic) isolation: 800 VDC, minimum

TMR Digital Output Modules

The digital output is designed to provide current to field devices, so the field power supply must be connected to each output point of the field terminal.

Each TMR digital output (DO) module receives the output signal from the main processor on each of the three channels. Then a special quadruple output circuit on the module votes for each group of three signals. The circuit generates a voting output signal and transmits it to the field terminal. The quadruple voter circuit provides multiple redundancies for all critical signal paths, thus ensuring safety and maximum availability.

In addition, ongoing diagnosis is performed on each channel and circuit of the TMR digital output module. Any diagnostic failure on any channel will activate the "fault" indicator, which in turn activates the chassis alarm signal. The fault indicator only indicates channel faults, not module faults. Ensure that the module can operate normally when a single fault occurs and can continue to operate normally when certain multiple faults occur.

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