Measurement Computing Data Translation DT3034, User Manual

Page: 38 / 178

Attaching and Configuring a Screw Terminal Panel
37
Configuring Resistors R1 to R16 - Bias Return
Resistor locations R1 to R16 connect the low side of analog input channels to analog ground.
These resistor locations are typically used when connecting differential inputs to analog input
channels 0 to 15, where R1 corresponds to analog input channel 0, and R16 corresponds to
analog input channel 15.
The high side of the corresponding analog input channels returns the source input impedance
through the bias return resistors to the low side of the channels, and then to analog ground.
Typical resistor values are 1 k

to 100 k

depending on the application. Refer to page 46 for
an example of using bias return resistors.
Configuring Resistors R17 to R32 - Current Shunt
Resistor locations R17 to R32 are typically used to convert current to voltage on channels 0 to
15, where R17 corresponds to analog input channel 0, and R32 corresponds to analog input
channel 15.
These resistor locations connect the high side to the low side of the corresponding channels,
thereby acting as shunts. If, for example, you add a 250

resistor to location R17, and connect
a 4 to 20 mA current loop input to channel 0, the input range is converted to 1 to 5 V. Note
that, depending on your application, you may need to use resistors R1 to R16 with resistors
R17 to R32 for proper operation. Refer to
page 49 for an example of using current shunt
resistors.