Error -1074118647 When Running NI-SCOPE Application

Issue Details

My NI-Scope code is running in a simple loop where there are no configuration VIs between my niScope Initiate VI and my niScope Read VI.
But when executing the code, I get:

Error -1074118647 occurred at niScope Multi Read Cluster VI:

Possible reason(s):
A previous acquisition is still in progress. If you are attempting to change an attribute, note you can only change fetch attributes while an acquisition is still in progress.

Status Code: -1074118647

Solution

• Remove the niScope Initiate VI to prevent a situation where the task is being initiated twice in one loop. This is because when using only the niScope Read VI, it will have performed the initiation of the task already.
• Replace the niScope Read VI with an niScope Fetch VI. When using the niScope Initiate VI there is no need to use the niScope Read VI. Instead you should use the niScope Fetch VI to fetch the data from the digitizer's onboard memory. Refer to Acquisition Functions for more detail.

Additional Information

This error is occurring because the task is attempting to be initiated twice. Specifically, both the niScope Initiate VI and the niScope Read VI are attempting to put the digitizer/scope into a state to fetch data. If you are acquiring large blocks of data or if there is a delay on the trigger, the niScope Read VI can execute before the acquisition started by the niScope Initiate VI is complete.

As niScope Initiate VI itself may take a significant amount of time compared to all other NI-SCOPE functions, you should not include it in a loop when repeatedly acquiring data. Ideally, your program should initialize one time. Otherwise, the error above will occur.