7830R digital output voltage

Hi,
I am using a 7830R DAQ card to work with MOSFETs as switches.
We have a 25-MOSFET array. Each MOSFET is controlled by a DIO line of the 7830R card.
When the DIO line is at 0V, the MOSFET is off, and when the DIO line is at 5V, the MOSFET is on.
However, the output voltage automatically drifts to 5V and gradually
turns on the MOSFET if I do not keep updating the voltage of the line.
Can I set the default output voltage at 0V once for all?
Thanks.
Guang

Gaung-
I believe some clearification is in order. Are your DIO lines floating to 5V while your FPGA VI is running or are they floating after the FPGA is reset (usually the cloase FPGA reference resets teh device)? The DIO lines are expected to float when not being explicitly written to. You have a few options:
1) Set the default power up states via the instruction in this post:
http://forums.ni.com/ni/board/message?board.id=170&message.id=221423#M221423
2) Dont reset your FPGA VI when you close it. This will continue to drive the digital lines in thier last state.
3) Use pull down resistors on the DIO lines in question to force lines to 0V when not being driven
Xaq
Applications Engineer
National Instruments

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Attachments:
DO example.vi ‏44 KB
schematic.png ‏16 KB

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Error 1 occurred at Dequeue Element in FinalCombined_2.vi
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LabVIEW: An input parameter is invalid. For example if the input is a path, the path might contain a character not allowed by the OS such as ? or @.
=========================
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