National Instruments 6023E - Manual (Page 111)

Appendix C Common Questions
© National Instruments Corporation C-5 6023E/6024E/6025E User Manual
after power on, and Table 4-3, I/O Signal Summary , shows that there is a
50 k
Ω pull-up resistor. This pull-up resistor sets the DIO(0) pin to a logic
high when the output is in a high impedance state.