Monday, April 26, 2010

Zapping

We now have a zapper at the factory. Similar in strength to a static shock you would feel in normal daily life, perhaps a little stronger. Voltmeter measures 1200-1800 v. The standard MA vision screener gets a reaction on the computer screen although it does not lose communication.

We tried it with another screener with the Ben-Board, which has a modified USB. It does not register on the computer screen. The Ben-Board has never been used in production and has not been thoroughly tested. It would need a month or more of testing.

Would the L1 program need to be changed to work with this board? How would we determine if this solution would work? Can all failures to communicate be blamed on ESD?


14 comments:

  1. The board is the std VS board with a special Ben program for a compliant USB.

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  2. Let's put a cable/capacitor assembly on the screeners and zap again.

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  3. About your questions gifford.
    1. they could change easily, but they have to want it. Ben code boards, and normal boards(as alexis tell me) uses a HID driver that is completly different from Virtual Serial Port driver as we sent to them. But we normally work with HID without problem, and it should be easy for them to change.
    2. you tell me about 1200v and 1800V. should be good to see specifications because zapper from L1ID works between 8000v and 16000V. And i am sure when board will arrive there will be applied ESD without any merci.
    3. I am preparing the report. Not all faliures should be blamed to ESD. the one i have seen in the field is without nobody touching it. Althout, there is also a ESD discharge that can be irradiated without touch the machine. But it's very few parameters in order to extract a conclusion.
    regards

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  4. Reno is sending 3 handcontrols to Billerica today to test for an interim solution. They will need to be used with the RevH board. There were 3 RevH boards remaining in Billerica when Josep left.

    Testing with the cable/capacitor has not returned any significant results yet. The factory still needs to establish a firm testing base so when they introduce plastic film they can measure and reproduce results.

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  5. We now have a base testing system established that will reproduce similar measurements. It takes about 100 zaps to get 1 failure.

    The grounded USB cables, with and without capacitors, did not change the results.

    A plastic film glued to the lid of the screener prevented the problem. We need to determine the optimum thickness and the best way to attach it.

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  6. We selected a clear plastic material to cover the lid of the screener. It is optimum thickness to prevent static problems while thin enough to adhere properly at the corners. It will cover most of the metal in the "touch area" on the top of the vision screener.

    We are preparing several pieces to be completed this week. We will send them to Mass to install in the field. I will advise tracking when they are shipped.

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  7. The plasticized covers left the factory on Friday. I will advise the UPS tracking number in USA as soon as I get it.

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  8. Ten plasticized covers are schedules to arrive in Billerica on Wednesday May 12. Tracking number ups.com:
    F0553644841

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  9. The covers are in Boston, scheduled to be delivered today. Please put them out into the field to see if they solve your problems sufficiently and post the results and feedback. Then we can determine the best way to proceed.

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  10. The covers were delivered to Billerica at 10AM on May 12. I look forward to hearing results of the field testing.

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  11. Looking over some past notes:
    One thing that our engineer, Josep, found during his visit to the Springfield site was that the computer system gave an error message of "Vision creeper not found" when starting the software. It was not related to anyone touching the vision screener. This requires the operator to reset the computer which, of course, annoys the operator. It is probably caused by the delay in reaching the server database. None of the errors he saw at Springfield were caused by an ESD event.

    This could be solved by changing the L1 software to not require a restart of the PC but only to search again for the vision screener. Or to allow more time to search for the screener connection. This would significantly reduce problems attributed to the vision screener.

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  12. Regarding the rework of your vision screeners to use a handcontrol, this has not been done before using a board with the "compliant USB" which you asked us to install last year. So it will require engineering and testing, plus we do not think it can be installed in the field, but should be carried out at the factory. A quotation for this rework was sent to Terry last week. It does not address the bi-directional communication which you mentioned, as I have not received sufficient details yet on your requirements.

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  13. The factory tested Keystone's Visionary software with the Mass vision screener and found that the software will operate the Mass screener. It may be helpful to download the Visionary software to understand better how it interacts with the screener. It can be downloaded at:
    http://keystoneview.com/index.php?option=com_content&view=article&id=127&Itemid=1

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  14. Josep did not hear from the L1 programmer and the Mass state programmer today as tentatively planned. He will be available on Wednesday morning for a meeting. The Mass state programmer is only available Monday and Wednesday morning.

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