Chapter 3
Configuring and Testing
SCXI-1502 User Manual
3-2
ni.com
Input Selection
The front end of the SCXI-1502 includes a software configurable switch
that allows you to programmatically connect the input channels of the
SCXI-1502 to either the front connector or internal ground. Refer to
Table 5-1,
NI-DAQmx Voltage Measurement Properties
for details about
the available input coupling modes supported by the SCXI-1502.
CJC Source/Value
When using a terminal block that has a CJ sensor for thermocouple
measurements, you can set the CJC source as internal, which scans the
sensor at the beginning of each measurement and scales the readings
accordingly.
Auto-Zero
Setting the Auto-zero mode to
Once
improves the accuracy of the
measurement. With auto-zero enabled, the inputs of the SCXI-1502 are
internally grounded. The driver makes a measurement when the task begins
and then subtracts the measured offset from all future measurements.
Configurable Settings in MAX
Note
If you are not using an NI ADE, using an NI ADE prior to version 8.1, or are using
an unlicensed copy of an NI ADE, additional dialog boxes from the NI License Manager
appear allowing you to create a task or global channel in unlicensed mode. These messages
continue to appear until you install version 8.1 or later of an NI ADE.
This section describes where you can access each software-configurable
setting in MAX. The location of the settings varies depending on the
version of NI-DAQmx you use. Refer to the
DAQ Getting Started Guide
and the
SCXI Quick Start Guide
for more information on installing and
configuring the hardware. You can use DAQ Assistant to graphically
configure common measurement tasks, channels, or scales.
NI-DAQmx
Using NI-DAQmx, you can configure software settings such as sensor type
and gain/input signal range in the following ways:
•
Task or global channel in MAX
•
Functions in your application
