Are inductive, magnetic, and capacitive proximity switches all passive sensors? Why? How do you determine it?
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RT. Why do I keep thinking that they are active contacts? Please clarify this
The detection principle has no direct relation to the type of contacts; if it is of electromagnetic or capacitive type, a power supply is definitely required.
Could you be more detailed? I’m not very familiar with this aspect :)
I found a blog online that was well-written; I’d like to recommend it: http://xuekuo.2008.blog.163.com/blog/static/31300731201491310841893/
Are passive contacts typically used in two-wire systems, while active contacts are used in three-wire systems?
It can be considered that the two-wire system uses passive contacts (the power supply comes from the DCS)； In the three-wire system, since it has PNP and NPN outputs, the signal (contact) returns to the DCS with a source. @jiaguoyun