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National Instruments Corporation
5
BNC-2115 Installation Guide
To connect AI signals to the NI PCI/PXI-60
XX
E and AT-MIO-64E-3
devices using the AI <16..55> BNC-2115 connectors, refer to the
Connecting Analog Input Signals
section.
To connect DIO signals to the NI PCI/PXI-6025E and AT-MIO-16DE-10
devices using the P0.<0..7>, P1.<0..7>, and P2.<0..7> BNC-2115
connectors, refer to the
Connecting Digital I/O Signals
section.
Connecting Analog Input Signals
National Instruments recommends that you use the BNC-2115 in
differential mode. If you need more analog inputs in your application than
are available using differential mode, you can configure your DAQ device
in single-ended mode and double the number of analog input channels.
Refer to the
Operating the BNC-2115 in Single-Ended Mode
for details. You can use the BNC-2115 to measure floating and
ground-referenced analog input signals in differential mode.
Measuring Floating Signal Sources
To measure floating signal sources, move the switch located below the
applicable analog input BNC to the floating source switch position labeled
FS. In the floating source switch position, the amplifier negative terminal
is connected to ground using a 5 k
Ω
resistor in parallel with a 0.1
µ
F
capacitor. Table 1 shows the BNC-2115 switch configuration options.
Note
Measuring floating signal sources, such as isolated battery-powered equipment,
with the GS setting results in incorrect measurements.