How do I capture a RS232 data stream while generating a pulse train?

[TwoFishes]

I need to start capturing data through an RS232 port then begin generating a pulse train and finally stop capturing the data stream. I would then like to be able to graph the parsed data and also send it to a file. I have found examples for pulse train generation using DAQmx which work form my purposes (counter outputs) but I can't figure out how to capture a section of RS232 data stream. I was trying to use I/O assistant in LabVIEW 7.0, but I can't capture more than one sample of the data stream. Any ideas?

[chilly_charly]

Could you be a bit more explicit : do you want to
- find how to use a serial port with LV ?
- synchronize serial readings to extract data from a continuous stream sent asynchronously by an instrument ?
- something else
I guess it is point n°2, but we need more detailled explanations.