© National Instruments Corporation
D-1
DAQCard-700 User Manual
Appendix D
Power-Management Modes
This appendix describes the power-management modes of the DAQCard-700.
•
Normal Mode—This is the normal operating mode of the DAQCard-700 in which all the
circuits are fully functional. This mode draws about 100 mA from the 5 V supply (about
500 mW).
•
Power-Down Mode—In this mode, the digital circuitry is powered on and is functional. The
analog input circuits are 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-700. 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 70 mA from the 5
V supply (about 350 mW).
Table D-1 shows the effects of different power-management modes on the DAQCard-700
circuits.
Table D-1. DAQCard-700 Power-Management Modes
Normal Mode
Power-Down Mode
Analog
Input
Functional. Defaults to bipolar
(
±
10 V) RSE. Protected to
±
30 V. Impedance > 1 G
Ω
.
Nonfunctional. Draws
negligible power. Protected
to
±
30 V. Impedance = 4.7 k
Ω
,
which is the input protection
resistance.
Calibration
Circuitry
Functional. Offset and Gain
values can be read from the card
information structure.
Functional. Offset and Gain
values can be read from the card
information structure.
Digital I/O
Functional. Digital Output
defaults to 0. Protected from
-0.5 to 5.5 V.
Functional. Digital Output
defaults to 0. Protected from
-0.5 to 5.5 V.
Counters
Functional. Initialize to
undefined states. Individual
counters of the 82C54 must be
fully programmed before use.
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.