How do I make a string indicator that scrolls it's data upwards like Hyperterminal?

[Keith Stetter]

Hello,

  I am trying to create a string indicator that scrolls old data up the way that Hyperterminal,ProComm ect  does. I am using a while loop to collect data and concantenateing the new data with the old on each loop iteration. I have tried to change the order of the concantenation and tried using the string reverse and rotate tools with no luck. If i could just force the indicator to scroll up instead of down I would be all set.

Any help would be greatly appreciated

Keith

[EdDickens]

Try this.



Storing the strings in an array lets you easily manipulate them and also lets you set a maximum "history" so it doesn't start eating up your memory.

This does not automatically scroll the display up, but you can do that manually or there is a property for a String control that will let you set the scroll position.

Message Edited by Ed Dickens on 02-02-2006 10:32 PM

[chilly_charly]

HeHe Ed,
I think the question was not about optimizing memory management, but merely how to scroll up ! 😄

Keith,
just add a TxtScrollPos property node into your loop, with a large enough constant wired as input and that will do the trick. See the attachment.

[EdDickens]

Well OK, so that ones a bit simpler. But what happens when your string goes over 100000 lines?

Anyway, memory management is always on my mind. (wow, did I just quote Willie Nelson?)

The reason I don't just use the Concantenate String is that it has the same memory allocation effect as the Build Array function. If you VI doesn't run for long periods of time, then this is the best solution. But if it's an application that will be running for days, that string will get huge. Using an array to hold the strings lets you set the size so you don't have to worry about it.

Ed

[smercurio_fc]

To continue the tangent, you could use queues to the same effect. I implemented a Memory Log library (for logging actions taken in my application) that initially used a managed string length but I then changed it to use a queue.