National Instruments NI 7831R 用户手册

4.

Reinsert the NI 7831R into the PXI/CompactPCI chassis or PCI 
computer. Refer to the Installing the Hardware section of the Getting 
Started with the NI 7831R document for installation instructions. 

5.

Plug in and power on the PXI/CompactPCI chassis or PCI computer.

After completing this procedure, a VI stored in flash memory does not load 
to the FPGA at power-on. You can use software to configure the NI 7831R 
if necessary. To return to the defaults of loading from flash memory, repeat 
the previous procedure but return switch 1 to the OFF position in step 3. 
You can use this switch to enable/disable the ability to load from flash. In 
addition to this switch, you must configure the device with the software to 
autoload.

When the NI 7831R is powered on with switch 1 in the ON position, the analog 

circuitry does not return properly calibrated data. Move the switch to the ON position only 
while you are using software to reconfigure the NI 7831R for the desired power-up 
behavior. Afterward, return switch 1 to the OFF position.

Two pins on each I/O connector supply 5 V from the computer power 
supply using a self-resetting fuse. The fuse resets automatically within a 
few seconds after the overcurrent condition is removed. The +5V pins are 
referenced to DGND and can power external digital circuitry. The 
NI 7831R has the following power rating:

+4.50 to +5.25 VDC at 1 A (250 mA max per +5V pin, 1 A max total for 
all +5V lines on the device)

Do not connect the +5V power pins directly to analog or digital ground or to any 

other voltage source on the NI 7831R or any other device under any circumstance. Doing 
so can damage the NI 7831R and the computer. NI is not liable for damage resulting from 
such a connection.