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NI 9758 User Manual
Each low-side driver channel automatically tests for open circuit conditions. When the low-side
switch is commanded open, the circuit is tested for an open condition. Upon detection of an open
circuit, an open circuit error flag will be reported. The error flag may be cleared by software.
Driver circuit operation is not affected by an open circuit error flag that is left asserted.
Each low-side driver channel automatically protects itself from an accidental short circuit to
battery. When the low-side switch is commanded closed, the circuit is tested for a short. Upon
detection of a short, a short circuit error flag will be reported for the channel and the channel will
be disabled until software clears the error flag. The short circuit error flag for each channel will
not be cleared while the switch is being commanded closed. It is strongly recommended that the
user not continually clear the short circuit error flags, as this may lead to driver circuit damage
in the event of an actual short circuit. Even though the short circuit detection and disable feature
is present, it is strongly recommended that the wiring harness include a 5 A automotive fuse for
four solenoids.
Figure 6.
Connecting General Purpose Solenoids to the Low-Side Driver Channels
Note
A CompactRIO controller may be powered by the same power source or by
an isolated power source. If the CompactRIO controller is powered by the same
battery used for cranking the engine, then it is possible that the battery voltage will
drop below 9 V during cranking, causing the CompactRIO controller to reset. This
can be prevented by using a small backup battery and a diode pack for the
CompactRIO controller.