Parallel Comunication to GPIB instrument

[mentanto]

Hi

We have a GPIB instrument (Agilent 33210A Function Generator) and we want communicate from 2 parallels process in the same vi, (2 parallel loops). In labview 2012

We try to use the "GPIB status" function to check when instrument is in listen mode. (We check the LACS bit to determine when the instrument is in listener mode)

In my program we have  a principal loop and a secondary loop. The principal writes different frequency data to the instrument and the secondary loop try to write a frequency when the instruments is "free".  Sometimes it's works and sometimes it doesn't work.

How is posibble to make it? Do anybody in here knows a smart way to do it?

Thanks you very much!

[crossrulz]

Make a third loop that does nothing but communicate with your instrument.  You can use a queue to send messages to that loop to request whatever action you need.  This will prevent your two parallel processes from interrupting each other.

[mentanto]

Thanks you for the answer!

But It's not possible a third loop. The file that I attachment it's only a test. Actually we can't modify the principal loop. We only can create a second parallel loop that check the status of the communication with the instrument. Our goal is that our process write and read data to  the Function Generator when it is free

Thanks

[Dennis_Knutson]

Use a VISA lock. Checking for listen mode seems like a fragile hack.

[Henrik_Volkers]

Sounds like a hack 😉

Do you have access to the main code? 

All it would need it is to replace the visa write vis used  to communicate with your generator with your own sub vi which is not reentrant and handle the looking.  

[mentanto]

Ha Ha Ha!  Don't worry! Everything is legally

Yes, I have access to the main code, but it's being developed by other group. My work try to add a parallel process to check the instrument status.

You give me a good idea man, thanks you!. And also thanks to Dennis.

You'll be hearing from me, soon. hopefully it will work

Greetings from Spain (Valencia)