Exchange data with TestStand from a python thread

[dug9000]

Probably the easiest way to pass data would be with a TestStand queue where you give it a name beginning with an '*' character so that it is shared across processes. See the API help for Engine.GetSyncManager() as a starting point. The sync manager API is also used by the synchronization step types (the queues created by them are one and the same).

-Doug

[User002]

Is their a way to pass an object reference from TestStand to a python script? Has anybody had success using IronPython (basically as a .NET wrapper). I'm not sure how to pass a COM object via the command line. It'd be great if you can directly pass a reference, like ThisContext, to a python script but I can't find anybody tackling this on the forums.

[flaborde]

I have not used IronPython; howerver, since it is only a .NET wrapper you can use COM Interop to communicate with TestStand. For more information on this, depending on your specific IronPython version see http://blogs.msdn.com/b/shrib/archive/2008/04/10/ole-automation-idispatch-support-in-ironpython.aspx

The name for the COM reference is "NationalInstruments.TestStand.Interop.API", the GUID can be found in the registry under HKEY_CLASSES_ROOT\CLSID (or HKEY_CLASSES_ROOT\Wow6432Node\CLSID in 64-bit systems), just search for the COM reference name.

[tmonaghan]

I have been trying to pass data to Teststand from python/pywin32 and the com interface.

I can connect to a running Teststand sequence which creates a queue "*GlobalQueue" and get a the created queue name, however i am unable to get data into the queue using the enqueue method.

Code

import win32api
import win32com.client
import pythoncom

QUEUE_NAME = "*GlobalQueue"

#Get Engine Reference.
testStandEngine = win32com.client.Dispatch("TestStand.Engine.1")
print ("TestStand Ver: ",str(testStandEngine.MajorVersion)+"."+str(testStandEngine.MinorVersion),"Ready")

#sync with TS engine
syncMgr = testStandEngine.GetSyncManager(QUEUE_NAME)

queue = syncMgr.GetQueue(QUEUE_NAME)
while queue == None:
    print("Unable to get queue:",QUEUE_NAME)
    queue = syncMgr.GetQueue(QUEUE_NAME)

print("Found Queue:",queue.Name)

# TS enqueue usage
# http://zone.ni.com/reference/en-XX/help/370052G-01/tssuppref/reftopics/queue_enqueue_m/
# Queue.Enqueue ( atFront, full Q Option, newElementPropObj, byRef, timeoutInSeconds, sequenceContextObj, processMsgs, waitRes, enqueueRes)

waitRes = -1
enqueueRes = -1
data = "test"
seqContext = None

#create queue object
queueObject = testStandEngine.NewPropertyObject(1, False, "", 0)
queueObject.SetValString("", 0, "Test");

print(queueObject.GetValString("",0))

#create sequence object.
seqObject = testStandEngine.NewPropertyObject(5, False, "", 0)
print(seqObject.GetTypeDefinition ("", 0))
queue.enqueue(False, 0, queueObject, False, 5, seqObject, True,waitRes,enqueueRes)

The error i get is an exception;

TestStand Ver: 14.0 Ready
Found Queue: *GlobalQueue
Test
None
Traceback (most recent call last):
File "C:\ts\pyTS.py", line 48, in <module>
queue.enqueue(False, 0, queueObject, False, 5, seqObject, True,waitRes,enqueueRes)
File "<COMObject GetQueue>", line 2, in enqueue
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, 'TSSync', None, None, 0, -2147467261), None)
>>>

I have tried using the OLEviewer and found the prototype.

Any help would be apprieciated.

Thanks in advance

Tim