Bus Interface; Power Requirement - National Instruments PC-LPM-16/PnP User Manual

Appendix A Specifications

Bus Interface

Power Requirement

Note:
Physical
Environment
Explanation of Analog Input Specifications
PC-LPM-16/PnP User Manual
Type.................................................... Slave
+5 VDC ( 10%).................................. 50 mA typ
+12 VDC ( 5%).................................. 15 mA typ
-12 VDC ( 5%) .................................. 15 mA typ
These numbers do not include an additional 1 A from the 5 V power supply.
The 50-pin I/O connector can draw 0.5 A from the +12 V supply.
Dimensions ......................................... 11.0 by 9.9 cm (4.4 by 3.9 in.)
I/O connector ...................................... 50-pin D male ribbon cable
Operating temperature......................... 0 to 70 C
Storage temperature ............................ -55 to 150 C
Relative humidity................................ 5% to 90% noncondensing
Relative accuracy is a measure of the linearity of an ADC. However,
relative accuracy is a tighter specification than a nonlinearity
specification. Relative accuracy indicates the maximum deviation from
a straight line for the analog-input-to-digital-output transfer curve. If a
ADC has been calibrated perfectly, then this straight line is the ideal
transfer function, and the relative accuracy specification indicates the
worst deviation from the ideal that the ADC permits.
A relative accuracy specification of 1 LSB is roughly equivalent to
(but not the same as) a 1/2 LSB nonlinearity or integral nonlinearity
specification because relative accuracy encompasses both nonlinearity
and variable quantization uncertainty, a quantity often mistakenly
assumed to be exactly 1/2 LSB. Although quantization uncertainty is
ideally 1/2 LSB, it can be different for each possible digital code and
is actually the analog width of each code. Thus, it is more specific to
use relative accuracy as a measure of linearity than it is to use what is
normally called nonlinearity, because relative accuracy ensures that the
connector
A-4 National Instruments Corporation