Chapter 2
BNC-2080 Board
© National Instruments Corporation
2-3
BNC-208X Series User Manual
Power Connections
Because the BNC-2080 board is an analog breakout board for both the MIO-16 and PC-LPM-16
boards, it has a flexible power connection scheme.
Switch S5 is responsible for selecting the power inputs from the I/O cable. Switch S5 is a three-
position switch that configures the BNC-2080 to connect to pins 33 (DGND) and 34 (+5 V) in
position
A
, to no I/O pins in position
B
, and to pins 49 (+5 V) and 50 (DGND) in position
C
.
Table 2-1 shows the setting to be used with each of the National Instruments data acquisition
boards.
Table 2-1. Switch S5 Settings for National Instruments Data Acquisition Boards
Board
S5 Setting
AT-MIO-16
AT-MIO-16D
AT-MIO-16F-5
AT-MIO-16X
A
A
A
A
MC-MIO-16
A
NB-MIO-16
NB-MIO-16X
PC-LPM-16
A
A
C
Warning:
If the data acquisition board does not use pins 33/34 or pins 49/50 for power
connections, set switch S5 to position
B
. Failure to set switch S5 to position
B
under
these conditions could result in damage to your external power supply, the
BNC-2080, the expansion board connected to the BNC-2080, and/or your computer.
National Instruments is
not
liable for damages resulting from such connections.
Analog Input
Each differential analog input has seven open positions for signal conditioning components. Six of
these positions are designated as resistors, and one is designated as a capacitor. The board is
shipped with jumpers in two positions for each input. The equivalent circuit of one input is shown
in Figure 2-3. The board can be used when the MIO-16 board is configured for both 16 single-
ended inputs and 8 differential inputs. For specific applications illustrating signal conditioning
with both single-ended and differential inputs, refer to the section titled
this chapter.
