Mickey
Lifetime Supporting Member
Yes but the four wire device does not connect the power supply's common to the PLC.
Some four wire devices require more power then a loop can provide. 4 wire devices can also be powered by different voltages (e.g. 120vac)
Less wiring for loop powered/3 wire then 4 wire.
I'm sure others with more knowledge of how and why vendors build their devices will give a more knowledgeable answer then mine.
Some four wire devices require more power then a loop can provide. 4 wire devices can also be powered by different voltages (e.g. 120vac)
Less wiring for loop powered/3 wire then 4 wire.
I'm sure others with more knowledge of how and why vendors build their devices will give a more knowledgeable answer then mine.
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