National Instruments NI PXI-7831R, User Manual

Page: 37 / 73

Chapter 2 Hardware Overview of the NI PXI-7831R
NI PXI-7831R User Manual 2-16 ni.com
devices. Because the NI PXI-7831R digital outputs provide a nominal
output swing of 0 to 3.3 V (3.3 V TTL), the NI PXI-7831R DIO lines
cannot drive 5 V CMOS logic levels. To interface to 5 V CMOS devices,
you must provide an external pull-up resistor to 5 V. This resistor pulls up
the 3.3 V digital output from the NI PXI-7831R to 5 V CMOS logic levels.
For detailed DIO specifications, refer to Appendix A,
Specifications .
Cautions Exceeding the maximum input voltage ratings, which are listed in Table B-2,
NI PXI-7831R I/O Signal Summary , can damage the NI PXI-7831R and the computer.
NI is not liable for any damage resulting from such signal connections.
Do not short the DIO lines of the NI PXI-7831R directly to power or to ground. Doing so
can damage the NI PXI-7831R by causing excessive current to flow through the DIO lines.
Refer to Appendix A,
Specifications , for more information. NI is not liable for any damage
resulting from such signal connections.
If required by your application, you can connect multiple NI PXI-7831R digital output
lines in parallel to provide higher current sourcing or sinking capability. If you connect
multiple digital output lines in parallel, your application must drive all of these lines
simultaneously to the same value. If you connect digital lines together and drive them to
different values, excessive current may flow through the DIO lines and damage the
NI PXI-7831R. Refer to Appendix A,
Specifications , for more information. NI is not liable
for any damage resulting from such signal connections.