LabVIEW 7.0 Bug List

LabVIEW 7.0 About Box

This list has been reported to NI as problems existing in LV 7.0. I am hoping to put all of these in a single place available to the info-labview community.

  1. Drop thru clicks from other applications cannot be disabled. Clicks from within LV do not drop thru but other classic applications will drop thru. NI has looked at this and cannot find the problem. The code appears to be correct.
    Platforms: Mac - Corrective Action Request filed

  2. Units bug
    Goal: Display temperature with degC and degF using one control
    1. create a thermometer indicator; show the digital display
    2. edit the digital display to replace it with a second thermometer
    3. add units(degC) to the first indicator.
    4. BUG: the second indicator has DegC units on its label but it displays Kelvin(temp. base unit) values on the scale. LV accepts to change the units of the second indicator to degF but values are not yet consistent with the first.
    Example VI
    Platforms: All

  3. Waveform Chart Drawing - Scott Hannahs <>
    Date: 3/11/2002
    On a waveform chart after the display is full and is scrolling horizontal, if one uses the "hand" cursor to drag the plot around lines are drawn from the new points to some arbitrary point in the plot. Releasing the hand pointer allows the scrolling to continue but the mess is still there until is scrolls off the screen
    Example VI
    Platforms: Mac and ???

  4. Three needle gauged - John Howard <>
    Date: Thu, 19 Jun 2003 08:12:43 -0400
    Here is the exact sequence that led to the crash:
    1. new blank vi
    2. drop down a 3D gauge control
    3. right click gauge, select "Properties", and Add two more Needles (so the gauge now has 3 needles).
    4. click OK
    LV crashes with an insane object. "Insane Backup Object FPHP+313C graphics(0x80) list (LIST)", about 3 of these (one for each needle?) and then an exception at FPsane line 319. The current work around is to add the needles one at a time. "I can make it happen on any of the numeric controls that you can add multiple pointers to. The Gauge, Meter, Knob, Dial, even the slide controls make it crash."
    Platforms: Win 2K, Win XP, Mac OS X, Mac OS 9
    Note: NI has released a fix for the bug causing insane object errors When adding or removing needles or sliders in properties dialog box. All you have to do is replace a LabVIEW llb. You can find the fix here.

  5. Copy of dir.mnu - PJ M <>
    Date: Thu, 19 Jun 2003 07:51:53 -0700 (PDT)
    Go to user.lib, create a copy of you original dir.mnu (→ "Copy of dir.mnu") and try to restart labview. Let me know if you succeed (tried on 2 machine with W2k and I cant). I got that one while installing my user.lib vis for lv6.1 and it took me a while to figure out what was going on.
    Platforms: Win 2K, Mac OS X

  6. End of Line Inconsistent in error messages - Paul F. Sullivan <>
    Date: Fri, 20 Jun 2003 05:04:51 -0400
    The end of line character is inconsistent in the error messages in LabVIEW 7.0. Some times it's a carriage return an sometimes it's a line feed. This causes a missing blank line in the displayed message (and indigestion for my legacy message parsing routine, which I solved by detecting each).
    LabVIEW 7.0:

    LabVIEW 6.0.2:
    Platforms: Mac OS X, Windows

  7. SubPanel Bug: Blinking not working through subpanel - PJ M <>
    Date: Mon, 29 Sep 2003 13:49:42 -0700 (PDT)
    The blinking property of controls is not working in subpanel. While running the subpaneled vi you end up with either the blinking state of the control or the non blinking state, but no blinking. It seemĘto affect every control (I tried it on Boolean, String, Numeric). If you run the enclosed library the main VI will run the blinky sub vi but you will not see the blinking. If you select from the windows list (even though it does not have a window and doesn't open one) it will start blinking! (the example does not have a stop button just abort)
    Example VI
    Platforms: Mac OS X, W2K

  8. Waveform Chart Slow down - Scott Hannahs <>
    Date: Tue, 17 Feb 2004 10:21:16 -0500
    There is an unusual performance hit in using a waveform chart. I have a chart with several plots on it and a lot of data. As soon as the chart fills performance goes south and CPU usage skyrockets. However if I make the history buffer 1 larger than the x scale displayed everything works fast?!!? Having that 1 undisplayed point out of 17000 makes that big a difference (we are talking an order of magnitude performance hit!).
    Example VI
    Platforms: Mac OS X, Mac OS 9

Weirdnesses/Unexpected Behavior

  1. DAQ AI Read Time Limit "Hart, Roger H." <>
    Apparently the time limit set for a hardware triggered AI acquisition is really "time limit" value MINUS the buffer size time. i.e. I was acquiring 4 secs of data on a hardware analog trigger with a 10 sec time limit.. and a buffer size 2.4 times # of scans. I couldn't get a single pulse to trigger.. but continuous pulses triggered fine. I finally figured out that the buffer size represented about 9.6 secs and a single pulse would trigger the acquisition only if it occured within 0.4 secs of the acquisition start. I had to increase the time limit value to 20 secs to get a 10.4 sec window for single pulse triggering.

  2. Format into String
    I've noticed a small quirk in the new "Format into String" function. As a default it puts spaces between the concentanted values, whether numbers or strings. This was causing some parsing problems for me and I discovered that it puts a space between the each of the format specificers in the format string. i.e. %d %s %d. The spaces are spaces and not specifiers (\s), so you have to look carefully to notice the small space between the specifiers. If you put a "Format into String" node in a diagram and expand it to have 3 numeric inputs. Then "Command-Click" on the Format terminal and select "Edit Format String" the default string will have spaces that you might not want.
    Status: Verified problem in LV 6.1 Platforms: All

  3. In Range/Coerce Function and NANs - Dave Boyd
    The coerce function does not have well defined behavior when presented with "Not A Number" (NaN).
    Example VI
    Platforms: All

  4. Boolean Array Operator on Empty Array - Uwe Frenz <>
    Date: Wed, 06 Feb 2002 14:51:55 +0100
    If an empty array is fed to the "AND BOOLEAN ARRAY" operator, the result is true. If is false for the "OR" operation which is the default-default value for booleans.
    Example VI
    Platforms: All

Problems from previous versions not tested with 7.0

  1. PID toolkit bad when proportional only control - Bruce Ammons <>
    Date: Thu, 10 May 2001 11:54:27 -0400
    I have found a few bugs in the toolkit. They showed up when I tried to do proportional only control. I found that the integral portion (which should always be zero for Kp only) would get set to a constant offset. NI has been notified, but I don't know if they have done anything about it.

    The problem is most noticeable when you exceed your limits. Set the proportional gain to a large value, and use a setpoint with a large error. The limits will be exceeded and the integral constant is adjusted to stay within the limits. Now, if you set the setpoint equal to the error, the output should be zero, but it isn't. It is still equal to whatever was used to compensate for the limit. This value is stored in a shift register in the integral routine. I ended up modifying it to always use zero, except to correct for exceeded limits.

    NI response: "I spoke the the Research & Development Engineer that will be dealing with your request for a change to the PID toolkit vi's. He was aware that for some applications this behavior was not expected nor wanted, and feels that he can change the behavior for your. I do not have a time estimate at this time, but the corrective action request is CAR 29UG1MBQ"
    Platforms: WinNT, Win98, Win2K, Mac
    No example posted since PID toolkit is not public

  2. Crash when uncheck "Show Menubar" A hard LabVIEW crash with VI's that are set to ''Size the Front Panel to the Width and Height of the Entire Screen'' with ''Window has Title Bar'', ''Show menu Bar'', ''Show Scroll Bar'' and ''Show Toolbar When Running'' all unchecked. It happens when the cursor arrow is moved to the Macintosh menu bar area and when clicking on it....wham it goes and the system recommends a new start.

    Info from Bien Entendu <>
    it just happens when you uncheck "show menubar" there is a conflict with the STF Fax software. so you have three options:

    1. don't use the fax software by disabling all the fax stf extensions in extension manager
    2. set show menubar to "on" and set a menu for every vi with a frontmost panel
    3. convince national to repair this bug or to correct the bug on "show menubar" which still shows a menubar when the option is unchecked(!) and by the way, ask them to remove this ridiculous and disgratious white bar on top of every VI(where the menubars are on the other platform)
    Example VI
    Platforms: Mac
    Status: Not checked in LV 7.0
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