2 questions about PXI-6509

[yiweihua2002]

Dear All:
       I want to ask two questions about PXI-6509:
   1?We can set PXI-6509 Power up state from MAX, I set port1 for input and the powerup state is tristate.In my using,I often leave the port1 not connect,and I use LabVIEW to read this port,I found the port1 data is not stabilize,some times it read 255,and some times it read 254,I do not know why.Whether I must use pull-up resistor or pull-down resistor for port1.
   2?The PXI-6509 can generate square,and how many frequency it can generate?

[flybear]

1.The tristate is useful for the output ports, however, for the input ports. it is meaningless.
2.The digital ports of 6509 is software-timed.So the frecueny depends on the maximal loop rate in windows,which is hundreds of Hz.
 
Best wishes!

[yiweihua2002]

Thank you flybear.
I have know the tristate is for the output ports.but if I use port for input,the pull-up resistor or pull-down resistor is needed?

[Sherman]

Pull-up or Pull-down is no need for input.

[yiweihua2002]

???????????????????????????????????????????PORT??????255????254

[Sherman]

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[yiweihua2002]

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[Sherman]

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