labview programming

[chaitanya1]

Running a sub vi inside a while loop and continuing loop execution without waiting for sub vi to complete execution.is this possible?bcoz has i have come across when subvi is executing the control won't come out of subvi.i mean to say, main while should keep on iterating by opening different instance of subvi.can anubody help.......

[Mark Smith]

VIs, due to the dataflow design, always block execution until they are complete unless you take specific steps to start and run them in a new thread. You accomplish this using VI server calls - The easiest is to get a static reference to the VI you want to execute, wire that into an invoke node, and select the Run VI method (I think, I'm working from memory and I don't have LabVIEW on this machine). Set the Wait Until Finished argument to false. Now, the VI will start and run in a new thread and the call to start the VI will return immediately. If you want to open the front panel, set control values on call, etc., you'll also need to do those with property and invoke nodes. All of the functions I just mentioned are on the Application Control palette.

Also, if you need to launch multiple copies of the same VI, it will have to marked reentrant and the method to launch is slightly different. You'll have to wire the static ref to a property node, get the VI name, and pass that into an OpenVI (once again, I think that's the name) function because you have to set the optiions flag on that functon to 0x8 to allow launching reentrant VIs.

More info here

http://digital.ni.co...6256C59006B57CC

Mark

[chaitanya1]

VIs, due to the dataflow design, always block execution until they are complete unless you take specific steps to start and run them in a new thread. You accomplish this using VI server calls - The easiest is to get a static reference to the VI you want to execute, wire that into an invoke node, and select the Run VI method (I think, I'm working from memory and I don't have LabVIEW on this machine). Set the Wait Until Finished argument to false. Now, the VI will start and run in a new thread and the call to start the VI will return immediately. If you want to open the front panel, set control values on call, etc., you'll also need to do those with property and invoke nodes. All of the functions I just mentioned are on the Application Control palette.

Also, if you need to launch multiple copies of the same VI, it will have to marked reentrant and the method to launch is slightly different. You'll have to wire the static ref to a property node, get the VI name, and pass that into an OpenVI (once again, I think that's the name) function because you have to set the optiions flag on that functon to 0x8 to allow launching reentrant VIs.

More info here

http://digital.ni.co...6256C59006B57CC

Mark

VIs, due to the dataflow design, always block execution until they are complete unless you take specific steps to start and run them in a new thread. You accomplish this using VI server calls - The easiest is to get a static reference to the VI you want to execute, wire that into an invoke node, and select the Run VI method (I think, I'm working from memory and I don't have LabVIEW on this machine). Set the Wait Until Finished argument to false. Now, the VI will start and run in a new thread and the call to start the VI will return immediately. If you want to open the front panel, set control values on call, etc., you'll also need to do those with property and invoke nodes. All of the functions I just mentioned are on the Application Control palette.

Also, if you need to launch multiple copies of the same VI, it will have to marked reentrant and the method to launch is slightly different. You'll have to wire the static ref to a property node, get the VI name, and pass that into an OpenVI (once again, I think that's the name) function because you have to set the optiions flag on that functon to 0x8 to allow launching reentrant VIs.

More info here

http://digital.ni.co...6256C59006B57CC

Mark

Thank you for your reply.... i tried its working