National Instruments BridgeVIEW

Chapter 6 Historical Data Logging and Extraction

You will display previously logged data, which is included in the

BridgeVIEW\Activity\Data directory. It contains a 25-minute run

of data. You can change the time axis to display the first minute of this

data.

3. Run the VI. The trend displays one minute of data. You can use the

panning tool to grab the plot and scroll to the left or right to show more

data. Hold down the <Shift> key while you pan to constrain the

movement to the horizontal direction.

4. Stop the VI.

5. Modify the Block Diagram to incorporate statistics.

a. In the block diagram, pop up on the wizard lock and select

Release Wizard Lock. Now, you can edit the diagram to

incorporate statistics into your data retrieval application.

b. Using a For Loop and the Historical Trend Statistics.vi

(Functions»Historical Data), build the diagram as shown below.

If you click and drag the Positioning tool inside the case structure

while holding down the <Ctrl> key, the diagram will expand to

give you some room to add the new diagram code.