©
National Instruments Corporation
5
NI TB-2709 Installation Guide
Figure 4.
NI TB-2709 Block Diagram
For more detailed descriptions of these signals, refer to the
S Series User
Manual
.
Additional signal configuration information is available in Measurement &
Automation Explorer (MAX). To access this information in MAX, select
your device under
Devices and Interfaces
, and click the
Device Routes
tab.
Measuring Floating Signals
You can use the TB-2709 to measure floating and ground-referenced
analog input signals. To measure floating signal sources, move the switch
located under the rubber-sealed door on the enclosure cover for the AI
channel you are using to the ON (floating source) switch position. In the
floating source switch position, the amplifier negative terminal connects to
ground through a 5 k
Ω
resistor in parallel with a 0.1
μ
F capacitor. Table 2
shows the TB-2709 switch configuration options.
Table 1.
TB-2709 Signal Descriptions
Signal Name
Reference
Direction
Description
AI <0..7>
AI GND
Input
Analog Input channels 0 through 7.
PFI 0/AI Start Trig
D GND
Input
As an input, this pin is a programmable
function input (PFI).
Output
As an output, this pin is the AI Start
Trigger signal.
AI <0..7> +
AI <0..7> –
Front Panel
SMB Connectors
DAQ Device
Signals
AI <0..7> GND
AI Start Trig
D GND
5 k
Ω
0.1
μ
F
