National Instruments Module SCXI-1503 - Manual (Page 27)

Chapter 3 Configuring and Testing
SCXI-1503 User Manual 3-2 ni.com
Input Coupling
The front end of the SCXI-1503 includes a software configurable switch
that allows you to programmatically connect the input channels of the
SCXI-1503 to either the front connector or internal ground. When using
autozero, the coupling mode is set automatically. Refer to Table 5-1,
NI-DAQmx Voltage Measurement Properties , for details about the
available input coupling modes supported by the SCXI-1503.
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-1503 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 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.