Scanning an ascii string for a start and end character

Question

I would like to watch data lines on a com port and pick off a part of a
line that starts with a "$" and ends with a CR. I would like the
felxibility to select different start and end characters also. Is this
doable with LabView? I have the com port monitoring done I need to
separate incoming strings. I can't count chacters because the data
lines varies in length each time the data line comes in. Thanks in
advance fir the help.
[email protected]

Answer 1

If you don't want to mess with having to decide whether or not you need to pre-pend a "\" to the character you are feeding into the match-pattern function then you could just do it all with byte arrays like in the attached example. The example also shows various ways that ASCII controls & indicators can be configured to allow you to more easily handle non-visible characters (just right-click on the front panel control/indicator and select normal, \ codes, hex or password).
As far as your question about the error code meaning, you can right-click on a front-panel error cluster and select the "explain error" option to see all the known causes of the error. You have to then interpret this in the context of what you were doing. When I drop an error cluster on a front panel, set status to Error and code to 85, I can right click on it, select "explain error" and get this:
"Error 85 occurred at an unidentified location
Possible reason(s):
LabVIEW:  Scan failed."
 ...and that sounds to me like (as a WAG) you might be trying to use the Scan From String function with input data that does not match the format string.
Attachments:
String Subset.vi ‏53 KB