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Chapter 4
50
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 STP300 screw terminal panel as shown in
this case, make sure that the low side of the signal (
−
) is connected to ground at the signal
source, not at the STP300 screw terminal panel, and do not tie the two grounds together.
Figure 11: Connecting Differential Voltage Inputs from a Grounded Signal Source
(Shown for Channel 0)
Connecting Current Loop Inputs
shows how to connect a current loop input (channel 0, in this case) to the STP300
screw terminal panel.
Figure 12: Connecting Current Inputs (Shown for Channel 0)
TB18
Grounded
Signal
Source
+
-
TB1
TB2
Analog In 0
Analog In 0
Return
E
s
Signal Source
Ground V
g1
STP300 Panel
Resistor R1 should be installed for bias
return in case the external ground is floating.
R1
Analog Ground
STP300 Panel
TB1
Analog Input 0
Analog Input 0
Return
TB2
TB18
Analog Ground
4 to 20 mA
+V
CC
R1
R9
Use current shunt resistor R9 to convert current to voltage; 250
Ω
for 4 to 20 mA = 1
to 5 V. The common-side of the external loop supply must either connect to analog
ground or, if needed, to a bias return resistor (R1 in this case).
Содержание DT300 Series
Страница 1: ...DT300 Series UM 16501 T User s Manual Title Page ...
Страница 4: ......
Страница 10: ...Contents 10 ...
Страница 14: ...About this Manual 14 ...
Страница 15: ...15 1 Overview Features 16 Supported Software 18 Accessories 19 Getting Started Procedure 20 ...
Страница 21: ...Part 1 Getting Started ...
Страница 22: ......
Страница 58: ...Chapter 4 58 ...
Страница 69: ...Part 2 Using Your Board ...
Страница 70: ......
Страница 106: ...Chapter 6 106 ...
Страница 124: ...Chapter 8 124 ...
Страница 125: ...125 9 Troubleshooting General Checklist 126 Technical Support 128 If Your Board Needs Factory Service 129 ...
Страница 130: ...Chapter 9 130 ...
Страница 156: ...Appendix C 156 ...
Страница 164: ...Index 164 ...