Measurement Computing Data Translation DT3010 Series, User Manual, Page: 69 / 232

Chapter 4
68
Figure 19: Connecting Differential Voltage Inputs to the STP268-EC
(Shown for Channel 0)
Note that since they measure the difference between the signals at the high (+) and low (
−
)
inputs, differential connections usually cancel any common-mode voltages, leaving only the
signal. However, if you are using a grounded signal source and ground loop problems arise,
connect the differential signals to the DT740 or STP268 screw terminal panel as shown in
Figure 20 , or to the STP268-EC as shown in Figure 21 .
Make sure that the low side of the signal (
−
) is connected to ground at the signal source, not at
the screw terminal panel, and do not tie the two grounds together.
TB52
TB52
Floating
Signal
Source
+
−
TB34
Analog In 0
Analog In 0
Return
Analog Ground
User-
Supplied
Resistor
R
s
TB34
Analog In 0
Analog In 0 Return
Analog Ground
R
v
R
s
Bridge
+
−
DC Supply
Supply a bias return resistor to
connect the low side of channel
0 to analog ground.
A)
B)
STP268-EC Panel
TB68
TB68