I am new in LabVIEW, and I need to generate a pseudo random bit sequence with PXIe-5644 PXI Vector Signal Transceiver to supply this signal into an optical laser. Do you have any suggestion, advise to follow?
Realistically, if you are new to LabVIEW, I would prioritize becoming familiar with programming in LabVIEW before trying to tackle a project like this. I'd propose checking out this page for familiarizing yourself with basic LabVIEW concepts. Ultimately, however, I think you would greatly benefit from taking full training courses (at least LabVIEW Core I and II), which you can complete online or in person.
Once you have determined how to generate the sequence mathematically, you'll then need to learn how to generate the signal from the 5644 VST. You'll need the RFSG driver to do so. I would suggest checking out the following example as a decent starting place:
1) From any LabVIEW window in the menu bar, select Help » Find Examples...
2) Navigate to Hardware Input and Output » Modular Instruments » NI-RFSG » Arbitrary Waveforms » RFSG Arbitrary Waveform Generation.vi
Out of curiosity, why does the optical laser require an RF signal? Is that for control of the laser? I am not familiar with optical lasers, so wanted to understand why this is necessary.