Multifunction DAQ

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USB-6009: 4k7 resistance = high impedance?

In the user guide for USB-6009 it says on page 17:
"Power-On States
At system startup and reset, the hardware sets all DIO lines to high-impedance inputs. The DAQ device does not drive the signal high or low. Each line has a weak pull-up resistor connected to it."

On page 15 is says:
"Source/Sink Information
The default configuration of the USB-6008/6009 DIO ports is open collector, allowing 5 V operation with an onboard 4.7kOhm pull-up resistor."

NI say that the lines are high-impedance. But then there is a weak pull-up resistor, and the value of that pull-up is 4.7kOhm!?! Is 4.7kOhm really considered the same as high-impedance?

Is there any way of turning off this 4.7kOhm pull-up resistor?

Jan Egil
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I feel a bit stupid now, but I actually had problems finding this forum... :-S
Now that I've found it I see that it's not only me that has problems with this pull-up resistor, and as far as I can see there is no way of disabling it.

Before I bought this box I read that the DIO ports are default high-impedance. NI can't really mean that 4.7kOhm pull-up is the same as high-impedance, can they?

-Jan Egil
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