Appendix E Power Management Modes; Table E-1. Daqcard-500 Power-Management Modes - National Instruments Corporation DAQCard-500 User Manual

Appendix E
Power-Management Modes
This appendix describes the power-management modes of the DAQCard-500.
• Normal Mode—This is the normal operating mode of the DAQCard-500 in which all the
circuits are fully functional. This mode draws about 60 mA from the 5 V supply (about
300 mW).
• Power-Down Mode—In this mode, the digital circuitry is powered on and is functional. The
analog input is powered down by setting the PWRDOWN bit in the PC Card Configuration
and Status Register. You can set the PWRDOWN bit by using the DAQPOWER utility that is
shipped with NI-DAQ. Use DAQPOWER-D to power down and DAQPOWER-U to power up
the DAQCard-500. This utility is also available in Windows and is installed whenever you
install NI-DAQ. Typically, the analog supplies are not reduced to zero; negligible power is
supplied to the analog circuits. This mode draws about 20 mA from the 5 V supply (about
100 mW).
Table E-1 shows the effects of different power-management modes on the DAQCard-500
circuits.

Table E-1. DAQCard-500 Power-Management Modes

Analog
Input
Digital I/O
Counters
© National Instruments Corporation
Normal Mode
Functional. Protected
to ±25 V. Impedance
> 1 G .
Functional. Protected
from -0.5 to 5.5 V.
Functional. Initialize
to undefined states.
Individual counters of
the 82C54 must be
fully programmed
before use. Protected
from -0.5 to 5.5 V.
E-1
Power-Down Mode
Nonfunctional. Draws
negligible power.
Protected to ±25 V.
Impedance = 4.7 k ,
which is the input
protection resistance.
Functional. Protected
from -0.5 to 5.5 V.
Functional. Initialize
to undefined states.
Individual counters of
the 82C54 must be
fully programmed
before use. Protected
from -0.5 to 5.5 V.
DAQCard-500 User Manual