Write user message displays old data bug

Technical NI LabVIEW
1

I found that using the Write User Message VI was displaying old data. For example, if it was blank and I sent a 1 then nothing was displayed. Then I sent a 2 and 1 was displayed. Then I sent a 2 again and 2 was displayed.

After digging into the library, the problem is in WPI_DriverStationLCDWrite User Message.vi. The text cache has no dependencies on anything else, and
gets executed prior to setting the line text. This means it sends the previous update’s line, not the current update.

I’ve attached a version which puts the text cache in a sequence structure so that it is called at the correct time. Put it in C:\Program Files\National Instruments\LabVIEW 8.6\vi.lib\Rock Robotics\WPI\DriverStation\DriverStationLCD to fix the problem.

I reported this to the WPILIB tracker http://firstforge.wpi.edu/sf/tracker/do/viewArtifact/projects.wpilib/tracker.wpilib_labview_bugs/artf1335

WPI_DriverStationLCDWrite User Message.vi (15 KB)


WPI_DriverStationLCDWrite User Message.vi (15 KB)

2

Thanks Joe - I will be the owner of that tracker.

3

Thanks. I discovered this myself two days ago and I was just going on here to let everyone know. I see you beat me to it.