LabView 6i serial problem

[sopwith]

I have an old instrument that uses the serial port for communication, I have written a VI for this and it has been working well on computers that use Windows 95 and 98. However we recently had to use a computer that has Windows 2000 and the VI has ceased to work. I was wondering if there are issues with LabView,Rs232 and NT. I can get the VI to work if I use the LabView in the trace mode but when it is in normal mode it won't work. I have tried to trace what is happening using Procom to monitor the serial ports but this does not show up any errors apart from sometimes missing the command string and never catching the return string from the instrument. In the VI I have the Tx and the Rx part of the programme in seperate sequence frames, so one should be finished before the other is called. I hope there are some experts out there that can help me. I was wondering if I have a rogue computer as I do not have any other computers running NT to test the VI on.

 

[Spasomat]

Hi,

serial port under different windows versions in labview isn't always easy.
Have you tried the discussionforum in the NI developer zone?
h**p://www.ni.com/devzone/lvzone/discussionforum.htm
There are quite a few topics about serial communicaion problems.

Have fun,

Spasomat

 

[sopwith]

Not elegant but solved

Thanks Spasomat I did try NI's website but did'nt see any solution.I have however solved the problem by inserting a delay between the serial set up VI and the Tx VI. It seems that before the port was set up the TX VI was being activated.A flaw LabView when used with fast processors?? or as said earlier a problem with this particular computer.

 

[abifar]

hi

about this problem I can tell you ,it is very comolicated to explain but it related to Windows NT kernel becouse this kenel dont allowed to user or programs to have free access to hardware then there are some checking before any session of send or recive of data to prefferial equipments like as Rs232 com lpt or even Grafice card it is reason of NT is too slow OS for run a multimedia matreial same as 3D plays ....
for solve of of these problem you need to go C programming interface and some thing in NT ..

babak

 

[thenguyenhoangs]

Re: Not elegant but solved

Thanks Spasomat I did try NI's website but did'nt see any solution.I have however solved the problem by inserting a delay between the serial set up VI and the Tx VI. It seems that before the port was set up the TX VI was being activated.A flaw LabView when used with fast processors?? or as said earlier a problem with this particular computer.

Try the forum LAVA - LabVIEW Advanced Virtual Architecture

**broken link removed**

Always propose the questions with the man on forum, it's better.