NI 9219 Operating Instructions 16 ni.com
for lead wire resistance. Refer to Figure9 for an illustration of the
connections.
Figure 9. Connections in 2-Wire Resistance and Quarter-Bridge Modes
Half-Bridge and Full-Bridge Modes
Half-Bridge and Full-Bridge modes use the internal voltage
excitation to set the input range of the ADC and return voltage
readings that are proportional to the excitation level. The internal
excitation voltage is nominally 2.5 V but it varies based on the
resistance of the sensor. Refer to the Specifications section for
more information about excitation levels.
In Half-Bridge mode, the HI input is referenced to EX–.
InFull-Bridge mode, the ADC reads the HI and LO inputs
differentially. Refer to Figure10 for an illustration of the
connections.
LO
R
Wire
Wire I
ADC
I
HI
NI 9219