Chapter 3
Signal Connections
VXI-SC-1102 User Manual
3-26
©
National Instruments Corporation
is
±
11 V. This common-mode input range for either positive or negative
channel input is the maximum input voltage (relative to CGND) that
will result in a valid measurement. Each channel includes input
protection circuitry to withstand the accidental application of voltages
up to ±42 VAC peak or VDC.
Warning:
Exceeding the input damage level (±42 VAC peak or VDC between input
channels and chassis ground) can damage the VXI-SC-1102, the VXIbus,
and the VXI-MIO module. National Instruments is
NOT
liable for any
injuries resulting from such signal connections.
Applying a voltage greater than
±
42 VAC peak or VDC to the VXI-SC-1102
is an electrical shock hazard. National Instruments is
NOT
liable for any
damages or injuries resulting from such voltage application.
Note:
Exceeding the differential or common-mode input channel ranges results
in a distorted signal measurement.
Ground-Referencing Your Signals
Your input signals can be either ground-referenced, as shown in
Figure 3-2, or floating, as shown in Figure 3-3. Before you connect
your thermocouple or any other signal, determine whether it is
floating or ground-referenced. If it is a floating signal, you must
ground-reference the signal in one of two ways. You can connect the
negative channel input to chassis ground as shown in Figure 3-3 or you
can use the clamping resistors on a VXI-TB Series terminal block. The
VXI-TB Series terminal block may also have a resistor pack for pulling
up the positive inputs for open-thermocouple detection. Consult the
terminal block installation guide for details.
Do not ground signals which are already ground-referenced; doing so
will result in a ground loop, which adversely affects your measurement
accuracy.
!
Summary of Contents for VXI-SC-1000
Page 1: ...VXI SC 1000...
