Power Supplies and Overcurrent Conditions
If a short circuit occurs, the current through DO can exceed the current rating for the
power supply and the maximum continuous output current for the NI-9472.
If the power supply you are using with the NI-9472 cannot supply more than 14 A,
the module may be damaged if a short circuit condition occurs.
Detecting an Overcurrent Condition
If a device connected to the module is not working while the channel is on, the
module channel may be in an overcurrent state. Neither the software nor the
module LEDs indicate if an overcurrent condition occurs. A channel LED may be on
even if the channel is off because of an overcurrent condition.
To determine if the channel is in an overcurrent state, measure the voltage between
DO and Vsup. If the voltage is equal to the voltage of the external power supply
connected to the module, the channel is in an overcurrent state.
Resetting Channels after an Overcurrent Condition
After you have determined and fixed the cause of an overcurrent condition, reset the
channel by turning it off.
Alternatively, you can disconnect the external power supply from the chassis.
However, doing so disconnects power from all the module channels.
Normal operation can resume after you correct the overcurrent condition and reset
the channel.
Where to Go Next
NI Services
to find support resources including documentation,
downloads, and troubleshooting and application development self-help such as
tutorials and examples.
Visit
to learn about NI service offerings such as calibration options,
repair, and replacement.
© National Instruments
13
NI-9472 Getting Started
