Looking for USB/serial device

Discussion in 'General Hardware' started by 03jh01, Nov 23, 2010.

  1. 03jh01

    03jh01 Geek Trainee

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    Hello everyone,

    I have been looking for a certain piece of hardware, but cannot find what I need anywhere. In fact, I don't even know if it exists! I shall explain what I need briefly if I can...

    We are a laundry, and the check in workstations are where the garments are checked into the plant. Basically, the workers scan the garments (an RFID chip is present in each garment), the details for that garment appear on screen, the screen is locked, they then have to press an unlock button on the touch screen monitors before they can scan the next garment.

    I am after a device that can be connected to each workstation's PC via usb or serial port connection, of which will do the job of the unlock button. Ideally, this should be a light barrier type system where by the workers can pass there hand through the light beam (thereby breaking it), a signal is sent to the PC, the program inteprets it and unlocks the screen.

    Having said that, I would very much welcome hearing about any mechanical systems that involve physical contact from the workers, as long as they can be connected to the computer, and perform the simple function of unlocking the screen. Any system that does the job is a welcomed idea!

    If anybody knows of a device that is capable of doing this, if you could let me know, I would very much appreciate it :). It is an extremely simple device in theory, so there must be something out there somewhere.

    Thank you very much,
    Jason.
     
  2. 03jh01

    03jh01 Geek Trainee

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    Can anyone help...Please :).
     
  3. henry222

    henry222 Geek

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    You haven't explained this "unlock button" -
    - Is it part of the PC software that your firm bought? (and now find inconvenient...?)
    1) go back to the software writer.

    On a safety point, if you connect workstations (in a laundry =notoriously "wet"), it will be far safer to use a pneumatic switch . . .. something like an industrial-size button, but it can be operated with a gloved-hand, yet can't be operated by mistake. Also being somewhat Robust it can be screwed to a bracket where convenient.

    The same "convenience" applies to a light-guard (you describe), but these are easily operated by flying dirt, flotsum etc, which might be present in yr plant - and would be an error . . . . for this reason light-barriers are usuall used to switch-OFF equipment (ie perform safety).

    Each pneumatic switch will need to be connected (via narrow-bore plastic tubing), to the PC, although you could jury-rig a contraption to press the PC's keyboard (eg "Enter"), just to prove it is acceptable to staff under work-pressure. (ie a single station I expect).
    Eventually you have to go to the software provider for "proper" switch connections, maybe using an interface card. This may not be cheap, hence the suggestion you "trial" the technique using your existing keyboard, however "strange it will look" - the Operator won't see it, being only interested in the next item.
    . . . . . Only then, you finalise the new technique . . . .
    I would suggest the "new interface card" should provide some "feedback" such as a relay output, so you can provide lights to alert the operator when the RFID is accepted ( and? alerting "wrong codes" or, "not identified")
    Since these changes will be costly (as always), adding all extra features should be done in one go.

    I expect you should allow for several workstations, although you didn't say how big your laundry is. I assume it must be considerable, to employ RFID. Presumabvly these chips don't mind a thorough boiling....? Do tell.

    The external arrangements can be USB - but something internal is "better" IMHO.
    Also, USB connectors are not very "industrial" in my opinion.
    That's enough.
     
  4. 03jh01

    03jh01 Geek Trainee

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    Thank you very much takign the time to respond in such depth.

    We are actually using touch screens, so no keyboards are present on these workstations. The reason we want to get rid of the 'on screen' unlock button is that the touch screens get worn out. The workers are pressing the same point on the screens every day, and, even if they move it around every so often, the screens quickly wear out.

    The way I understand it, the unlock button simply clears the screen of all the previously scanned garment's data, and allows the next garment to be scanned by disabling an error condition in the code. Basically, the (very simple) code to 'unlock' the screen for the next scan is run in reaction to the button's click event (obviously!). Now, instead of being run when the button is clicked, it needs to run when a single is sent from this device that I am looking for. How the signal is interpreted is unimportant at this stage, they/we just require a device that is capable of sending a basic signal based whether the user pressed a physical button or broke the light beam etc. All the scanning process and such is working perfectly well. We just need this very simple device that can send a signal to the PC, we can then worry about running the unlock code in response to that signal.

    Furthermore, I don't think the issue with water will be a safety issue in this case. These workstations are in the initial sorting area. The garments that are dealt with have come straight from the back of a lorry. They haven't gone near a washer (or any water for that matter) yet. So, I don't think that will be an issue.

    The laundry is quite a large one yes, and RFID tags can endure very high temperatures (I cannot remember the exact figure :)). Although, apparently, they do have a finite lifetime.

    The reason the IT team mentioned the light barrier as being ideal is that it won't get worn out due to lack of physical contact from the workers. Plus, we have a mechanical system in our clean room (where garments are hung up on hangars affter being washed). Basically, the workers scans the garment, put the garment on the hangar, then pass there hand throguh a lightbeam. This act sends the garment on it's way (the machine takes the garment to the dryer).

    Obviously, this is a purely mechanical function; they want one that can be plugged into a computer, and used to send a signal to a computer, which can then is interpreted to unlock the screen.

    I don't think accidental operation of the light beam would be an issue. Nothing much can go wrong if the beam is accidentally broken. For example, if the garment has been scanned and the beam is accidentally broken, the screen is unlocked. This isn't a problem as the screen needed to be unlocked for the next scan. If a garment hasn't been scanned in, and the beam is accidentally broken, nothing will happen as there is no garment data on screen to clear.

    Do you know of any specific companies and specific items that are capable of sending this signal. Like I said, it just needs to send a single signal to the PC. The function of the unlock button, and the function of this device, is very very basic in the grand scheme of things. A light beam is prefered still, but a physical button would be acceptable if there were issue findign the light beam device.

    I shall run past the rest of the IT team what you mentioned in the previous post. The seem quite set on a USB/Serial port device I think though :). All the scanners, readers and computer hardware in the plant seem to run from serial ports and virtual usb ports.

    Thanks a lot for your time; once again.
     

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