Chapter 4
Analog Input
4-38
ni.com
Figure 4-25.
Connecting to the USB-6215/6216/6218 in Referenced
Single-Ended Mode
In an referenced single-ended connection config
u
ration, each inp
u
t channel
is meas
u
red with respect to AI GND.
Taking Non-Referenced Single-Ended Measurements
To reach a compromise between referenced single-ended and differential
meas
u
rements, yo
u
can
u
se an non-referenced single-ended meas
u
rement
config
u
ration. This config
u
ration allows for a remote sense for the negative
(–) inp
u
t of the instr
u
mentation amplifier (PGIA) that is shared among all
channels config
u
red for non-referenced single-ended mode. The behavior
of this config
u
ration is similar to that of referenced single-ended
connections, except it provides improved noise rejection. Fig
u
re 4-26
shows an non-referenced single-ended connection config
u
ration.
Figure 4-26.
Connecting to the USB-6215/6216/6218 in Non-Referenced
Single-Ended Mode
In non-referenced single-ended connection config
u
ration, each inp
u
t
channel is meas
u
red with respect to AI SENSE.
AI 1
AI 2
AI GND
U
S
B-6215/6216/6218
M
u
x
ADC
PGIA
AI 1
AI 0
AI GND
M
u
x
ADC
PGIA
AI
S
EN
S
E
U
S
B-6215/6216/6218
