National Instruments AT E Series

AppendixC CommonQuestions

ATE Series User Manual C-10 ni.com

Whata rethe power-on states of the PFI and DIO lines on the I/O

connector?

Atsystem power-on and reset, both the PFI and DIO lines are set to high

impedance bythe hardware.This means that the devicecircuitry is not

activelydriving the output either high or low. However,these lines may

havepull-up or pull-down resistors connected to them as shown in

Tables4-2 to 4-5. These resistors weakly pull the output to either a logic

highor logic low state. For example, DIO(0) is in the high impedance state

after poweron, and Table 4-2, I/O Signal Summary for the AT E Series,

showsthat there is a 50 kΩpull-up resistor. This pull-up resistor sets the

DIO(0) pin to a logic high when the output is in a high-impedance state.