Chapter 3
Connector and LED Information
©
National Instruments Corporation
3-7
+5 V Power Source
The +5 V terminals on the I/O connector 5 V referenced to
D GND. Use these terminals to power external circuitry. A self-resetting
fuse protects the supply from overcurrent conditions. The fuse resets
automatically within a few seconds after the overcurrent condition is
removed.
Caution
Never
connect the +5 V power terminals to analog or digital ground or to any
other voltage source on the M Series device or any other device. Doing so can damage the
device and the computer. NI is
not
liable for damage resulting from such a connection.
The power rating on most devices is +4.75 to +5.25 VDC at 1 A.
Refer to the specifications document for your device to obtain the device
power rating.
Note
(NI PCIe-625
x
Devices Only)
M Series PCI Express devices supply less than 1 A of
+5 V power unless you use the disk drive power connector.
Note
The NI 6221 (37-pin) device does
not
have a +5 V terminal.
USB Chassis Ground
For EMC compliance, the chassis of the USB M Series device
must
be
connected to earth ground through the chassis ground.