National Instruments cFP-PWM-520 用户手册

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页码 19
© National Instruments Corp.
7
FP-PWM-520 and cFP-PWM-520
Disconnect the external power supply from the 
[c]FP-PWM-520.
Remove the [c]FP-PWM-520 from the terminal base or 
backplane.
Power off the network module connected to the 
[c]FP-PWM-520.
Normal operation can resume after you correct the short-circuit 
condition.
Overcurrent Protection
Each output channel on the [c]FP-PWM-520 has circuitry that 
protects it from current surges resulting from short circuits. 
Whether the module suffers damage from 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 current surges
If the level of current through the output terminal is higher than the 
guaranteed trip current for the module, 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 level of current through 
the output terminal is higher than the minimum possible trip 
current and lower than the guaranteed trip current, the state of the 
channel is indeterminate and depends on factors such as the current 
level, the temperature, and the power supply.
Inrush currents that exist for less than the trip time do not trip the 
protection circuitry. Refer to the 
 section for more 
information about the maximum continuous output current, trip 
current, and trip time.
Power Supplies and Overcurrent Conditions
If a short circuit occurs, the current through an output terminal can 
exceed the current rating for the power supply and the maximum 
continuous current for the [c]FP-PWM-520.
If the power supply you are using with the [c]FP-PWM-520 cannot 
supply more than the guaranteed trip current, the module may be 
damaged if a short circuit occurs.