Unsupported Ivi Class Driver

[eromero]

We developed a new ivi class driver (for counters) and everything works well, the problem comes when we try to use the ivi tool step type to acces functions such as Reset, selftest Get/Set attributes etc. When we use this functions we get the following error

Error executing substep 'Post'.
An exception occurred calling 'RunStep' in 'ISubstep' of 'TestStand Ivi Step Types 1.0 Type Library'
An error occurred while executing the step.
Component Works IVI Control Error: The IVI operation failed for logical name 'SampleCounter'.
Details: The session handle is invalid or refers to a session that is not from a supported IVI class driver.
Source: TSIviStepTypes

The strange thing is that the functions Close and init with options in ivi to
ols work very well..so what's the problem with the functions reset, selftest, etc..
With this functions we can't even access the generic driver code because the error shows up before we can get to the code in debbigging mode. Any ideas?.

[btejani]

eromero,

I sounds like there's either an error in the configuration for SampleCounter, or that the IviStepTypes only support the DMM, Scope, Switch, FGen, and DCPwr class drivers.

If you could send/post your ivi.ini file and your driver, I'd be happy to check it out and see if there's a configuration issue. If you don't want to post it to DevZone, you can e-mail it directly to instrument.driver@ni.com.

As for why the init and close functions work, but not the others, I will investigate further.

One option to get your application to work is to not use the IviStepTypes. You can still use the driver using C function calls directly through the DLL. This will still work, but may not give you all of the features
of the step types.

Thanks,

Bankim Tejani
Instrument Drivers/IVI
National Instruments

[btejani]

Just as a follow-up, the Ivi Step Types in Teststand will only work with their current classes (DMM, Scope, Switch, FGen, and DCPwr). A feature request has been submitted for custom-class support in the Step Types.

You should use your counter class using C function calls through the DLL.

The Init and Close functions should not work either, but may be enabled due to the specifics of your implementation. There is nothing in the Step Type that enables that to work.

Thanks,
--Bankim