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 Application Notes later in this chapter.