LabVIEW
Increasing Num Legend Rows crashes LV if Stacked Chart
what??oh ,no!
in my case it seemed that the best way to achiece my vi function is to use this Property.
but now NI tell us it is blocked
can anybody show me any method to substitute this property?
thx so much!
It is not "necessary" to use a shift register for the waveform chart refnum, but I do consider it best practice. I have a couple reasons...
Inplaceness: When ever an item is connected to both sides of a loop (and the wire is not branched within the loop), a shift register forces the LabVIEW compiler to perform all actions on that data "in place", meaning LabVIEW doesn't copy the data in the wire if it modifies it. LabVIEW is constantly trying to optimize for in-placeness on its own for efficiency, but a shift register helps reinforce a good optimization.
Data Integrity: This is most important if I needed to use the wire after it passes through a loop. A While Loop isn't a good example because it always runs at least once, but if later on in my application I decided to change a loop into a For loop, there is the possibility that a For Loop can run 0 times. Most likely, I would want the data passed into the loop to be passed through the For loop, even if it ran 0 times. When using Shift Registers, that data does propagate, if using tunnels, the For Loop outputs the default value for the data type.
There is no way (that I know of) to programmatically changing the Stacked vs Overlay mode for a chart, other than having two charts and hiding/showing the appropriate one. Here is an example.
Cheers,
Message Edited by Spex on 05-13-2008 04:27 PM
Inplaceness: When ever an item is connected to both sides of a loop (and the wire is not branched within the loop), a shift register forces the LabVIEW compiler to perform all actions on that data "in place", meaning LabVIEW doesn't copy the data in the wire if it modifies it. LabVIEW is constantly trying to optimize for in-placeness on its own for efficiency, but a shift register helps reinforce a good optimization.
Data Integrity: This is most important if I needed to use the wire after it passes through a loop. A While Loop isn't a good example because it always runs at least once, but if later on in my application I decided to change a loop into a For loop, there is the possibility that a For Loop can run 0 times. Most likely, I would want the data passed into the loop to be passed through the For loop, even if it ran 0 times. When using Shift Registers, that data does propagate, if using tunnels, the For Loop outputs the default value for the data type.
There is no way (that I know of) to programmatically changing the Stacked vs Overlay mode for a chart, other than having two charts and hiding/showing the appropriate one. Here is an example.
Cheers,
Message Edited by Spex on 05-13-2008 04:27 PM
