VISA - com interface

[rajagopal]

hi

the attached program is used to test switches.

the firsat switch tests properly ( there is communication between the com1 and labview VISA).

but from the 2nd switch ( from loop 3 of the inner sequence), i get a null string.

i am expecting something like HSYNC: 256(when switch2 is at position 1, got it once, but guess missing the timing somewhere bcos the next time its not working)

and i get a null string everytime except for once or twice

pls advice!!

[LoganS]

Have you tried using NI-SPY to see where your application is erroring out? If you have never used it before here is a simple tutorial:

NI SPY Tutorial

I would also recommend that if you cannot find the source of your errors that you save the spy log as a .spy file and post it in response to this post. Let me know if that helps.

Logan S.

[rajagopal]

hi

got the output but getting them in highlight execution mode!!

guess time out problem. how to make the visa read wait until all data is obtained?

ram

[LoganS]

There is a property node called "Bytes at Serial Port". You could set up you application to wait until there are a specific number of bytes at the serial port, then perform your reads. That's the easiest option that I can think of.

Logan S.