National Instruments NI 9472 - Manual (Page 14)

NI 9472/9474 14 ni.com
I/O Protection
The NI 9472/9474 is short-circuit proof in accordance with
IEC 1131-2 and provides overcurrent protection.
Understanding Short-Circuit-Proof Devices
Each channel on the NI 9472/9474 has circuitry that protects it
from current surges resulting from short circuits. Whether the
module suffers damage from these overcurrent conditions depends
on the following factors:
• The amount of current through the channel
• The amount of time the current is above the current limit
• The frequency of the current surges
When the amount of current through the DO terminal or pin is
greater than 13 A, the channel trips and goes into an overcurrent
state. In an overcurrent state, the channel turns off and the module
is not damaged. If the current through DO is between 6 A and 13 A,
the state of the channel is indeterminate and depends on factors
such as the current level, the temperature, and the power supply.
Higher inrush currents that exist for less than the trip time do not
trip the protection circuitry. Refer to the
Specifications section for