National Instruments BNC -2140 - Manual (Page 16)

Chapter 3 Signal Connections
BNC-2140 User Manual 3-4 © National Instruments Corporation
Note This BNC-2140 pin assignment maps to the pin assignment of the DSA device you
are connecting to the BNC-2140. Refer to your DSA device user manual for the
pin assignments specific to your device connection.
Table 3-2 shows the pin assignments for the internal 68-pin I/O connector.
Refer to Figure 3-1 for the pin assignments for the 68-pin connector.
Caution Connections that exceed any of the maximum ratings of input or output signals
on the BNC-2140 accessory can damage not only the BNC-2140, but also the DSA
plug-in device and the computer as well. Maximum input ratings for each signal
are given in Appendix A,
Specifications . National Instruments is not liable for any
damages resulting from signal connections exceeding maximum ratings.
Table 3-2. 68-Pin Analog I/O Connector Signal Descriptions
Signal Name Reference Direction Description
AIGND — — Analog Input Ground—These pins are the reference
point for single-ended measurements in SE mode
and the bias current return point for differential
measurements.
+ACH<0..3> AIGND Input +Analog Input Channel 0 through 3.
–ACH<0..3> AIGND Input –Analog Input Channel 0 through 3.
+DAC0OUT –DAC0OUT Output +Analog Output Channel 0.
–DAC0OUT +DAC0OUT Output –Analog Output Channel 0.
+DAC1OUT –DAC1OUT Output +Analog Output Channel 1.
–DAC1OUT +DAC1OUT Output –Analog Output Channel 1.
AOGND — — Analog Output Ground—The analog output
voltages are ultimately referenced to this node.
DGND — — Digital Ground—This pin supplies the reference for
the +5 VDC supply.
+5 V DGND Output +5 VDC Source—These pins are fused for up to
0.5 A of +5 V supply on the DSA plug-in device.
The fuse is self-resetting. This source powers the
ICP circuits of the BNC-2140.
NOTE: For +ACH<0..3>, –ACH<0..3>, +DAC0OUT, –DAC0OUT, +DAC1OUT, and –DAC1OUT descriptions see
Table 3-1.
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