viInstallHandler for event callbacks issue

[nsr]

My app register callbacks for two events IO_COMPLETION and SERVICE_REQ (two viInstallHandler calls one after other). This perfectly works with the old version GPIB version 1. and VISA 2.1 but do not work with VISA 2.6.1 and GPIB driver NI488 2.2.1.
However, if my application only registers for IO_COMPLETION, the call back function is triggered after viWrite for command "*IDN?\n".
What needs to be done if both of the events to trigger the callbacks in a session?

[Dan_Mondrik]

Please verify which NI-488 version you have - do you mean that you have NI-488.2 2.1? (I don't think that 2.2.1 exists.) If my guess is correct, you should upgrade to NI-488.2 2.2 at www.ni.com/downloads. There were some fixes related specifically to this bug.

While you're at it, I suggest upgrading to NI-VISA 3.1. There have been a handful of GPIB-related bug fixes in that upgrade as well.

Dan Mondrik
National Instruments

[nsr]

Thanks Dan. I downloaded the NI-VISA-3.0.1 (for 98). I am able to run my app.