VISA: Parallel threads and locking instruments

[OnlyOne]

Hello,

i have 50 instruments that are controlled in two threads running at the same time.

Thread 1: Only VISA write (configuration of the instruments)

Thread 2: Visa write and Visa read (read measurement from instrument)

Can i now simply add the "Visa Lock Async VI" before the write and "Visa Unlock" at the end?

Thread 1: Visa Lock -> Write -> Visa Unlock

Thread 2: Visa Lock -> Write -> Read -> Visa Unlock

Thanks

[crossrulz]

It is really best if you can put all of the instrument control into a single thread.  That way you don't have to play these lock-do something-unlock games.  A Queued Message Handler works wonderfully for this situation.  But if you insist on not doing that (I know there are situations where you can't), then a Semaphore is really the way to go.

[OnlyOne]

Thanks for the help.

But it is also working with the Visa lock/unlock?

Using sempahores makes it very unreadable as i have to create new input/outputs to all VIs for the semaphores.

And the Visa addresses are already available for lock/unlock.

[Duffy2007]

Hello OnlyOne,

yes this should work.

What you can also try is to set read and write to synchronous mode

Choosing between Synchronous and Asynchronous VISA Functions

Hope this helps a little bit.