Callback event handling does not work for Service Request VISA events

[MGustafsson]

Hello,

I'm controllig an instrument over GPIB, using NI-VISA 4.4.1. Using the IO_COMPLETION event with a handler function works fine. However, trying the same with SERVICE_REQ events, I get the error "VI_ERROR_NSUP_MECH: The specified mechanism is not supported for the given event type" upon enabling the event. Is this the expected and intended behavior? I haven't seen anything suggesting so in the VISA documentation.

Best regards

Martin Gustafsson

[Davidek]

Hi Martin

For the moment this looks like it is expected behavior. A case for the implementation of the callback for the IO_COMPLETION event is in the works, but I can't say when or even if it will be completed. Sorry for the inconvenience.

Best Regards

David

NISW