User manual

Chapter 2 Connecting Signals
© National Instruments Corporation 2-5 BNC-2090A User Manual
Refer to Chapter 3, Signal Conditioning, for information about building
additional signal-conditioning circuitry, such as filters and attenuators,
in the open-component positions.
Measuring Ground-Referenced Signals in
Single-Ended Input Mode
A grounded signal source is connected in some way to the building system
ground; therefore, the signal source is already connected to a common
ground point with respect to the DAQ device (assuming the host computer
is plugged into the same power system). The non-isolated outputs of
instruments and devices that plug into the building power system fall into
this category.
When measuring ground-referenced signals, the external signal supplies its
own reference ground point and the DAQ device should not supply one.
Therefore, configure the DAQ device for the nonreferenced single-ended
(NRSE) mode, in which all of the signal grounds are tied to AI SENSE,
which connects to the negative input of the instrumentation amplifier on the
DAQ device.
Refer to Chapter 3, Signal Conditioning, for information about building
additional signal-conditioning circuitry, such as filters and attenuators, in
the open-component positions.
Connecting AO, APFI 0, and PFI 0 Signals
Use the BNC-2090A BNC connectors on the front panel to connect
AO <0..1>, APFI 0, and PFI 0 signals to your DAQ device. Refer to the
E Series User Manual or the M Series User Manual for information about
the use of these signals.