Example 1: Logging a Temperature Signal

You can use LabVIEW SignalExpress to log signals you acquire from various devices and instruments. The following procedure describes how to log a temperature signal from an NI-DAQmx device. This example assumes you have a thermocouple temperature sensor connected to physical channel ai0 of an NI-DAQmx device.

Note  You can install NI-DAQmx software from the National Instruments Device Driver DVD, or you can download the latest version of NI-DAQmx software from ni.com/downloads.

Complete the following steps to use LabVIEW SignalExpress to acquire a temperature signal from the device:

1. Launch LabVIEW SignalExpress and select File»New Project to open a new LabVIEW SignalExpress project.
2. Select Add Step»Acquire Signals»DAQmx Acquire»Analog Input»Temperature»Thermocouple to add the DAQmx Acquire step to the Project View. The Add Channels To Task dialog box appears.
3. In the Add Channels To Task dialog box, select ai0 under Dev1 (Device Name) and click the OK button. The Step Setup tab updates to display Dev1_ai0 in the list of channels, and Thermocouple Setup configuration options appear to the right of the list of channels.
4. Use the Thermocouple Setup options to configure the step. Select the Thermocouple Type you are using, and select deg F from the Scaled Units pull-down menu to specify to measure the temperature in degrees Fahrenheit.
5. After you configure the step, click the Record toolbar button. The Logging Signals Selection dialog box appears.
6. In the Logging Signals Selection dialog box, expand Thermocouple in the Signals to include tree and place a checkmark in the Dev1_ai0 checkbox.
7. Click the OK button to close the dialog box and begin recording the signal. A new log appears in the Logged Data window.
8. Switch to the Data View tab and drag the log from the Logged Data window to the Data View tab to view the progress of the log.

Note  You also can drag the Thermocouple output of the DAQmx Acquire step to the Data View tab to display the current value of the signal.

9. Click the Record or the Stop button to stop logging the signal.
10. Select File»Save Project to save the project.

Note  When you save a project that contains logs, LabVIEW SignalExpress saves the logs with the project. LabVIEW SignalExpress also saves log files in the .tdms file format to a location you specify on the Logging page of the Options dialog box.

This example describes how to start and stop logging by clicking a button. However, you might want to start and stop logging based on when a signal meets certain conditions. Example 2: Logging a Temperature Signal with Start and Stop Conditions describes how to configure logging with start and stop conditions in LabVIEW SignalExpress.