User Manual

Operation Theory 29
due to the variation of the conver-sion time of the A/D con-
verters.
Table 4-1 and 4-2 illustrate the ideal transfer characteristics of var-
ious input ranges of DAQ\PXI-20XX. The converted digital codes
for DAQ\PXI-2010 are 14-bit and 2’s complement, and here we
present the codes as hexa-decimal numbers. Note that the last 2
bits of the transferred data, which are the synchronous digital input
(SDI), should be ignored when retrieving the analog data.
Description Bipolar Analog Input Range Digital code
Full-scale Range ±10V ±5V ±2.5V ±1.25V
Least significant bit 1.22mV 0.61mV 0.305mV 0.153mV
FSR-1LSB 9.9988V 4.9994V 2.4997V 1.2499V 1FFF
Midscale +1LSB 1.22mV 0.61mV 0.305mV 0.153mV 0001
Midscale 0V 0V 0V 0V 0000
Midscale –1LSB -1.22mV -0.61mV -0.305mV -0.153mV 3FFF
-FSR -10V -5V -2.5V -1.25V 2000
Table 4-1: Bipolar analog input range and the output digital code on DAQ/
PXI-2010 (Note that the last 2 digital codes are SDI<1..0>)
Description Unipolar Analog Input Range Digital code
Full-scale Range 0V to 10V 0 to +5V 0 to +2.5V 0 to +1.25V
Least significant bit 0.61mV 0.305mV 0.153mV 76.3uV
FSR-1LSB 9.9994V 4.9997V 2.9999V 1.2499V 1FFF
Midscale +1LSB 5.00061V 2.50031V 1.25015V 625.08mV 0001
Midscale 5V 2.5V 1.25V 625mV 0000
Midscale –1LSB 4.99939V 2.49970V 1.24985V 624.92mV 3FFF
-FSR 0V 0V 0V 0V 2000
Table 4-2: Unipolar analog input range and the output digital code on DAQ/
PXI-2010 (Note that the last 2 digital codes are SDI<1..0>)