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Point monitoring system... — Parallax Forums

Point monitoring system...

starionstarion Posts: 27
edited 2007-03-07 00:41 in General Discussion
I know I can certainly do this with Parallax products, but I simply do not have the time at the moment.

I need a ready-made system that will monitor points (normally closed contacts) to generate a door prop alarm via ethernet to a PC-based software (multiple users) if the door is held open too long (user settable time). I do not need a full-blown access control system (which will do this), but simply something to monitor the status of the doors over a network.

I would love to sit down and build this, but right now I don't have the time and I just need to throw some money at it to complete a project.

Can anyone point me to a manufacturer of such a thing? Or even something that might be able to be modified slightly to serve the purpose?

Comments

  • starionstarion Posts: 27
    edited 2007-02-12 00:47
    I found this, anybody want to comment on whether this looks like it would work?

    www.saelig.com/miva/merchant.mvc?Screen=PROD&Product_Code=IO002&Category_Code=IO

    The only question I have about this is that the inputs are 5V logic levels and some of these doors are 50-100 feet away from where the controller would be located. I don't think voltage drop would be an issue, but noise on the line could be a problem.
  • tommytommy Posts: 84
    edited 2007-02-12 06:38
    golly.· someone has thought of almost everything...

    . I just read the first half of the manual, and this gizmo really lets your computer do physical things --- both output-wise, and with inputs.
    . page seven has "accessories", one of which is an 8-channel input adapter that will accept AC and/or DC signals, and will send just 5 volts into this gizmo...· on the way to your computer.

    . I have no idea what the screen might look like, nor how to set it up - but the physical details look well thought out.· If you're already using an ethernet network of some kind - "this is your baby".

    tommy·
  • RGuyserRGuyser Posts: 90
    edited 2007-02-13 08:58
    tommy- do you have a pc physically near the door?

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  • starionstarion Posts: 27
    edited 2007-03-04 15:42
    I went ahead and purchased the board I mentioned above from Saelig. No problems whatsoever with their online ordering. The board is made by Elexor. This thing is slick. I also bought an input board. I spent around $140 total and had some software written for it in just a couple of hours on the Mac using RealBasic. The instructions and specs are very well detailed from Elexor.

    Elexor also provides a free download (PC only) testing utility for the board so you can set up the parameters and write them to the on board EEPROM. This allows you to "configure" the board the way you want and simply write some software in your favorite language to listen for the points (or send to them if you have an output board).

    The price was a little bit higher than I wanted, but all in all it was very easy to get going. Now I have some network controllable project ideas to work on...
  • kjennejohnkjennejohn Posts: 171
    edited 2007-03-06 20:42
    Hi.
    You might want to try this next time:
    awce.com/gp3.htm

    It's a $50 board with a PIC on that communicates with a PC over the serial port. It plugs into a breadboard, but could just as easily be soldered to a "mother board" designed for it. The maker claims you can read voltages and pin states, then have the PC make decisions and change pin outputs to control various items. It has a continuous PWM channel for motor control, among other things. He says this can be programmed by many different compilers. It can even be controlled in a simple BASIC program using serial commands. The point of interest to you may be the ability to control it from an ASP Web page. Is this web page control going to work for you?

    END TWO CENTS.
    kenjj
  • starionstarion Posts: 27
    edited 2007-03-07 00:33
    Actually, that looks pretty interesting, but doesn't fit what we needed. We needed to monitor door contact opening and closings remotely over a network. The Elexor board is perfect for that. Although if the PC were located at each door, the above solution would work.

    Basically we have 6 doors in a high school that have contacts on them all run back to a central panel in an electrical room that happens to house one of the network switches for that floor of the school, so it was real convenient to tap into that.
  • T ChapT Chap Posts: 4,223
    edited 2007-03-07 00:41
    What about wireless, maybe Xbee. A processor/Xbee at each door sends a signal at some amount of time open or open/close event, the receiver Xbee sends the address to a very simple application that alarms that the specific location is open, which can even data log over some time period.

    oops, I forgot you wanted of the shelf


    X10 might be a good option.

    Post Edited (originator) : 3/7/2007 12:49:47 AM GMT
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