TestStand 3.1 Run Selected Steps generates Visa error -1073807346?

[jap9711]

When using Run Selected Step in TestStand 3.1 to interactively execute previous steps in a sequence a Visa error (-1073807346 The given session or object reference is invalid.) is generated even though the selected step has previously executed with no errors.

Some history:

The sequence in question was developed with TestStand 2.0 and LabView 6.1 and does not exhibit the above mentioned issue. The error began after migration to TestStand 3.1 and LabView 7.1. The sequence executes without errors in all other conditions. 

[RayFarmer]

Hi,

Where are you obtaining the the Visa session from? (I am assuming you are getting a Visa error because you are executing some VISA function in your code module.)

What do you mean by "execute previous steps"

Regards

Ray Farmer

[jap9711]

The error occurs when the sequence is halted and a step that has already been executed is highlighted and the Run Selected Step options is initiated.

I am not using explict Visa calls in the code modules. The instrument handles are established with Call Library Function Nodes. The Initialize routines for the instruments are contained in the setup of the main sequence and the handles are passed to TestStand and stored in globals.

jap9711

[RayFarmer]

Hi,

When your sequence halts, does that mean it's closed the visa sessions and if so when running the selected steps are you running the setup with the open visa sessions or are you just reusing the sessions stored in the Station Globals (I assuming when you said globals you were referring to Station Globals).

Regards

Ray Farmer

[jap9711]

In this case "halting" is accomplished by an inserted breakpoint or a failure at a measure step. I am reusing the visa session stored in the sequence file globals. The visa session is not intended to be closed until the completetion of the sequence.

jap9711 

[DWeiland]

Hi jap9711,

I would recommend simply stepping into the code and looking at the value being used for the Session ID. Place a break point on the step which is throwing the error, then Step Into the LabVIEW code. Turn on Highlight Execution, and place a probe on the wire holding the Session ID. Does the value you see here make sense?

Let us know jap9711, Thanks!