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National Instruments Corporation
31
SCC-68 User Guide
Configure Global Virtual Channels
If you want to use virtual channels in multiple NI-DAQmx tasks or
applications, configure global virtual channels with the DAQ Assistant.
You can launch the DAQ Assistant to create a global virtual channel in
MAX or in LabVIEW.
•
To open the DAQ Assistant in MAX, right-click
Data Neighborhood
and select
Create New
. In the Create New window, select
NI-DAQmx
Global Virtual Channel
and click
Next
.
•
To open the DAQ Assistant directly in LabVIEW to create a global
virtual channel, drop a
DAQmx Global Channel
control on the front
panel, right-click it, and select
New DAQmx Channel
.
The DAQ Assistant prompts you to create a new global virtual channel by
selecting an I/O type, such as analog input, the measurement or generation
to perform, the sensor applicable for that measurement, and the physical
channel from which to create a global virtual channel.
The DAQ Assistant prompts you to create a new global virtual channel.
1.
Select an I/O type, such as analog input.
2.
Select the measurement or generation to perform.
3.
Choose the sensor to use, if applicable for that measurement. A dialog
box opens for the task you have specified.
4.
Select the physical channel from which to create a global virtual
channel. Alternatively, you can copy information from an existing
global virtual channel. Click
Next
.
5.
Type the new global virtual channel name. Click
Finish
.
6.
Configure the onboard CJC sensor, if necessary.
To use the onboard CJC sensor for thermocouple measurements,
ensure that the CJC sensor is wired to AI 7, then select
Built-In
for the
CJC source. If this option is not available, check your configuration.
For more information, refer to the
Configuring the SCC-68
section. For
CJC sensor wiring instructions, refer to the
Using the Temperature
Sensor for Cold-Junction Compensation (CJC)
section.
7.
Select the terminal configuration. Refer to the
Analog Input
Measurement Considerations
section for more information about this
setting.
8.
Save your configuration.
9.
Click
Test
. Verify your data in the window that opens. If the data is
incorrect, verify the settings in the DAQ Assistant window.