GPIB timeout only when using multiple devices

[vgravel]

Hello,

I have a system using multiple GPIB device (about 5) all connected to the same slot. If I use any of them alone, I have no problem.

The problem occurs when one of the instrument is performing a task that can take some time (1 to 15 seconds). The two of the other instrument are giving me a timeout error. These instrument are Newport ESP300 and PI E-710, both are stages controller.

I read every instrument in its own loop running in parallel.

Anybody with an idea? 

Thanks in advance!

[Dennis_Knutson]

GPIB is not designed for parallel operation. What kind of mechanism do you have (if any) to ensure that there is only a single talker at a time?

[vgravel]

Well I don't have any... So this is probably the problem...

I tough it would be a better design to have 5 states machines, one for each instrument rather than I big one... Anything to suggest to fix that quickly?? Semaphore maybe?

Thanks for your quick help...