how can use usb?

[Dennis_Knutson]

Again, some basic understanding will go s long way. There are serial handshaking lines that you can query with a VISA property node. You will get asserted, unasserted, or unknown when you query the property. You should know that rs-232 is NOT ttl logic levels.

You've also been told three times now to use an arduino for a ready made solution.

[hamedi]

i wan to use serial port

when i perss the key LED is on.

please give me a vi that do this.

thank you so much.

[Dennis_Knutson]

It's unlikely that anyone will just give you the entire solution to your school work. With the property node, give it a try and if you run into problems, post what you have written with details on any issues you might be having.

Examples on the VISA property node do exist on this and the instrument control board. What search terms have you tried?