LabVIEW
why no timed loop in the mac version of LabView?
Solved!
Who forces you to use a Mac?
bamatennis wrote:Cause its extremely difficult to generate multiple signals at different rates at a high percison with out it.
This is very difficult (or impossible) on a general purpose OS. If you need high precision, you need LabVIEW RT or even FPGA.
Have you tried hardware timed signals instead?
What do you actually need to do? What kind of application is this? What kind of signals are you trying to generate? What are the various rates?
Please note that while the timed loop is available on Windows it is NOT the recommended way to do realtime timed control of things. Windows as general purpose OS is not suitable to do any real realtime operation. The timed loop exists as it was easier to develop and test under Windows than on the NI realtime targets in the first place and as it needs to be present on the host application when used in any of the realtime targets as you get otherwise broken arrows during development. But it doesn't and can't guarantee the realtime determinisme that it provides on the realtime targets. As such NI has always discouraged the use of the timed loop in normal desktop applications, although they have not gone to the trouble of disallowing it.
The timed loop does allow a somewhat more precise timing control than a simple software controlled loop, but if you expect it to be strictly below several ms accurate you are basically fooling yourself. Windows can and will at times interrupt LabVIEW in ways that will throw off the timeing of even the timed loop, no matter how deep NI tries to reach into the kernel to prevent that from happening. Even in Windows 10 exists some infrastructure that was caried over from Windows 3.x days for the sake of compatibility and that can simply lock up the system for many ms (some of them are refered to in the programming world as BFL, which stands for big f_cking locks).
So in short the reason why the timed loop is only available on Windows is, because it wasn't required in the other platforms as none of them supports development for realtime targets anyhow. Yes it also hooks pretty deep into the Windows interna to attempt to do some kind of accurate timing, but it has inherently not a much better timing accuracy than a normal LabVIEW loop, not on Windows anyways. On the realtime targets that is a different story. Just for the sake of code partability between Windows and other platforms the investment was considered way to high to try to port this feature to non-Windows systems as it doesn't really add many advantages to normal loops and Apple is indeed very averse about letting developers have that kind of access into the OS kernel, while under Linux it is generally a sure way to make your code VERY kernel version dependent.
