User`s manual

5.2.1 Common Ground / Single-Ended Inputs
Single-ended is the recommended configuration for common ground connections. However, if some of
your inputs are common ground and some are not, we recommend you use the differential mode. There is
no performance penalty (other than loss of channels) for using a differential input to measure a common
ground signal source. However the reverse is not true. Figure 5-4 below shows a recommended
connection diagram for a common ground / single-ended input system
Figure 5-4. Common Ground / Single-Ended Inputs
5.2.2 Common Ground / Differential Inputs
The use of differential inputs to monitor a signal source with a common ground is a acceptable
configuration though it requires more wiring and offers fewer channels than selecting a single-ended
configuration. Figure 5-5 below shows the recommended connections in this configuration.
Figure 5-5. Common Ground / Differential Inputs
15
+
-
Input
Amp
To A /D
A/D Board
I/O
Connector
LL GND
CH IN


Signal
Source with
Common Gnd
Optional wire
since signal source
and A/D board share
common ground
Signal source and A/D board
sharing common ground connected
to single-ended input.
+
-
Input
Amp
To A /D
A/D Board
I/O
Connector
LL GND
CH High
CH Low


Signal
Source with
Common Gnd
Optional wire
since signal source
and A/D board share
common ground
Required connection
of LL GND to CH Low
Si
g
nal source and A/D board
sharin
g
common
g
round connected
to differential input.