User manual

9 Chapter 3
3.3 Analog Input Connections
This section continues to describe how to make analog input signal con-
nections to the PCI-1715U card via the I/O connector.
Single-ended Channel Connections
The single-ended input configuration has only one signal wire for each
channel, and the measured voltage (Vm) is the voltage of the wire
referred to the common ground.
A signal source without a local ground is also called a “floating source”.
It is fairly simple to connect a single-ended channel to a floating signal
source. In this mode, the PCI-1715U card provides a reference ground
for external floating signal sources.
Figure 3-2 shows a single-ended channel connection between a floating
signal source and an input channel on the PCI-1715U card.
Figure 3.2: Single Ended Input Channel Connection
Table 3.1: I/O Connector Signal Description
Signal Name Reference Direction Description
AI<0…31> GND Input Analog Input Channels 0
through 31.
GND - - Ground
EXT_TRG GND Input A/D External Trigger.
ExternalInternal
Floating
Signal
Source
+
_
Vs
Multiplexers
AI31
AI1
AI0
PGIA
_
+
+
_
Vm
Measured
Voltage
I/O Connector
GND