topic Re: odd behavior from a Scan From String node inside a Diagram Disable structure in LabVIEW

odd behavior from a Scan From String node inside a Diagram Disable structure

jcarmody — Wed, 14 Aug 2019 14:44:04 GMT

A colleague showed me this:

The datatypes change when you put it into the Diagram Disable structure. It's fine if the string is inside the Enabled case.

Have you seen this? I'm using 32-Bit LabVIEW 2018.

Re: odd behavior from a Scan From String node inside a Diagram Disable structure

altenbach — Wed, 14 Aug 2019 14:53:26 GMT

Same in 2019. Curiously, it works fine once the output are wired with the correct datatypes.

Re: odd behavior from a Scan From String node inside a Diagram Disable structure

RavensFan — Wed, 14 Aug 2019 14:54:31 GMT

I see it in LV 2017 as well.

Very odd.

Re: odd behavior from a Scan From String node inside a Diagram Disable structure

altenbach — Wed, 14 Aug 2019 15:05:43 GMT

Of course the code is still highly ambiguous because there are many integer or floating point datatypes. Once you wire the desired datatype, things work as expected.

As said, is is also sufficient to wire a correct output and the terminals adapt.

Re: odd behavior from a Scan From String node inside a Diagram Disable structure

paul_cardinale — Wed, 14 Aug 2019 15:40:15 GMT

The first Scan From String works because, at edit time, it can read the value of the constant. It's probably looking for the source of the wire.

When the second Scan From String looks for the wire source, it finds the inside terminal of the tunnel, whose value at edit time is probably an empty string. Since other structures work OK, there is probably a bug in the Diagram Disable Structure that prevents (at edit time) the constant value from propagating through the tunnel.

Re: odd behavior from a Scan From String node inside a Diagram Disable structure

jcarmody — Wed, 14 Aug 2019 15:43:05 GMT

I just thought it was odd. Something about "disable" structures keeps the Scan From String node from finding the Scan string through a tunnel.

Re: odd behavior from a Scan From String node inside a Diagram Disable structure

oscarfonseca — Wed, 14 Aug 2019 21:22:13 GMT

Thanks for reporting this, Jim

I agree it's odd behavior and have filed CAR #744124 for the appropriate team to review it and follow-up.

Regards,