Chapter 3 Signal Connections
© National Instruments Corporation 3-31 DAQCard-1200 User Manual
Power ConnectionsPin 49 of the I/O connector supplies +5 V from the DAQCard-1200 power
supply. This pin is referenced to DGND. You can use the +5 V to power
external digital circuitry.
• Power rating 250 mA at +5 V maximum, fused to 1 A
Warning Do not directly connect this +5 V power pin to analog or digital ground or to any
other voltage source on the DAQCard-1200 or any other device. Doing so can
damage the DAQCard-1200 or your PC. National Instruments is NOT liable for any
damage due to incorrect power connections.
Pin 49 is fused for up to 1 A, but should be limited to 250 mA. The fuse is
a thermally resettable fuse which has an internal thermostat. This
thermostat opens when the current exceeds 1A and the temperature rises.
After some time, the thermostat cools down, the switch closes, and the +5
V is available once more. Opening this fuse does not necessarily damage
the DAQCard-1200. If you do not receive +5V, check for any shorts
between the +5 V power pin and ground.