National Instruments DAQ M Series - Manual (Page 60)

© National Instruments Corporation 6-1 NI 6236 User Manual
6
Digital Input and Output
NI 6236 devices have six static digital input lines, P0.<0..5>. These lines
also can be used as PFI inputs.
NI 6236 devices have four static digital output lines, P1.<0..3>. These lines
also can be used as PFI output. By default the digital output lines are
disabled (high impedance) on power up. Software can enable or disable the
entire port (software cannot enable individual lines). After the port is
enabled, you can individually configure each line to the following:
• Set a line to a static 0
• Set a line to a static 1
• Export a timing output signal to a line as a PFI pin
The voltage input and output levels and the current drive level of the DI and
DO lines are listed in the NI 6236 Specifications. Refer to Chapter 8,
PFI ,
for more information about PFI inputs and outputs.
I/O Protection
Each DI, DO, and PFI signal is protected against overvoltage,
undervoltage, and overcurrent conditions as well as ESD events. However,
you should avoid these fault conditions by following these guidelines.
• Do not connect any digital output line to any external signal source,
ground signal, or power supply.
• Understand the current requirements of the load connected to the
digital output lines. Do not exceed the specified current output limits
of the digital outputs. NI has several signal conditioning solutions for
digital applications requiring high current drive.
• Do not drive the digital input lines with voltages outside of its normal
operating range. The DI, DO, or PFI lines have a smaller operating
range than the AI signals.
• Treat the DAQ device as you would treat any static sensitive device.
Always properly ground yourself and the equipment when handling the
DAQ device or connecting to it.