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PLC controlled lighting system with PIR's — Parallax Forums

PLC controlled lighting system with PIR's

leeboy87leeboy87 Posts: 2
edited 2012-03-08 12:43 in Robotics
I have come up with a project to upgrade the lighting system for a building, whereby the lights will be switched on by PIR's which will act as inputs into a PLC (mistsubishi FX1S). Programming the PLC i should be fine with, but I am struggling with how to integrate the PIR output with the PLC. I also need to figure out how to activate the lights, im guessing to have the plc to activate a relay to bring in the supply to the lights within the room for that PIR.

If anyone could help me figure a solution I would be most grateful.

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-03-08 08:45
    First things first: which PIR are you using? Oh, and welcome to the forum!

    -Phil
  • leeboy87leeboy87 Posts: 2
    edited 2012-03-08 09:29
    Phil Pilgrim (PhiPi) wrote: »
    First things first: which PIR are you using? Oh, and welcome to the forum!

    -Phil


    Hi phil,

    That is one of the thing I need asisstance with, I am wondering is there better suited PIR's to utilise with the PLC?
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-03-08 09:58
    If the answer is not the Parallax PIR, this is probably the wrong forum to be asking the question. But let's compare Parallax's with another choice, selecting the aspects that may be important for your app:
    1. Parallax's PIR: Requires a 3-6VDC supply. Will not run on 12V or 24V. Has logic output levels. Does not come with an enclosure.
    2. Commercial motion sensors: Run from 24VDC. Have relay outputs compatible with PLC inputs. Come fully-enclosed.

    This is not to say that Parallax's PIR would not work. But it would require the addition of a voltage regulator, driver, and either a relay or optoisolator to be compatible with your PLC. Then you'd have to rig up an enclosure for it.

    -Phil
  • Ken GraceyKen Gracey Posts: 7,392
    edited 2012-03-08 11:18
    And there are two PIR sensor versions from Parallax, A and B.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-03-08 12:43
    Ken,

    'Didn't mean to cast Parallax's PIRs in a bad light with my comparison, only to point out that to "industrialize" them, i.e. to make them compatible with a typical PLC and provide environmental protection, will require some additional parts and effort. A PLC interface is a bit different than the three-pin servo-type interface we Parallaxians know and love.

    -Phil
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