Using HP34970A single point demo to measure several channels

[rossie]

I am using the HP34970A Single Point Demo.vi to measure several channels. I modified the Single Point.vi with a for loop so that it changes the channel every 2 seconds and performs the operation. The Single Point.vi works fine, but when I run it in the Single Point Demo, I only get a reading of the last channel. What can I do to make it read all the channels?

[Dennis_Knutson]

How did you modify Single Point? Are you creating an array of readings that needs to be returned. If you didn't, the subVI is only going to return the last result. You could also modify Single Point Demo and enclose Single Point with a for loop. Wire the voltage reading through the for loop and the autoindexing feature of for loops will automatically create your array.

[Dennis_Knutson]

How did you modify Single Point? Are you creating an array of readings that needs to be returned. If you didn't, the subVI is only going to return the last result. You could also modify Single Point Demo and enclose Single Point with a for loop. Wire the voltage reading through the for loop and the autoindexing feature of for loops will automatically create your array.

[rossie]

What do you mean by creating an array of readings?

[Dennis_Knutson]

If you want readings for multiple channels, then you're going to need to return an array of readings and not just a single one. You said that you modified the subVI by adding a for loop. The result indicator should be outside the for loop and since by default anything wired out through a for loop is auto-indexed into an array, your modification should have created an array of readings. If the reading indicator is inside of a for loop, it doesn't matter how many times you run it, when the for loop is done, it will only return the last result. But like I mentioned, I would modify the Demo program instead of the the subVI. Look at the attached picture and see if that's not what you want to do.