Leginon

Ed,

This indeed has happened before. array contains NaNs alone is caused by an instrument malfunction if this has being a working installation. The camera returns the image acquisition function call too early from some error. It may mean that you need to restart the Leginon Clients.

However, if you also get exposures taken at low mag afterward, it is an indication of user error in which you've allowed the program to process two queue such as acquiring hole images in "Hole" node as well as focusing and acquiring images in "Exposure". When queuing is used, we have to unlock the normal program thread to allow you to do things out of the order. See Queuing_option

We have seen this in the following cases:

1. "Hole" node does not have the setting "Wait for a node to process image" activated while "Exposure Targeting" queuing is off. With automated hole finding, both "Exposure/Focus" and "Hole" nodes would compete for the scope and camera to use. It looks like the scope is set to what "Hole" node wants while the camera is set to a state in between and Leginon client on the camera got confused and returned early.

2. All settings are properly set. However, the user requests "Hole Targeting" queue to be processed while "Exposure Targeting" queue is still be processed. Again, competition to the scope and camera causes the confusion.

You should check if you have a setting conflict if you understand what I just said here. Post your settings in "Hole", "Exposure Targeting" "Exposure", "Focus" here if you need help.

Since this kind of user error normally are produced when users got created with speeding up the process and it is hard to trace back what was done, you can also revert the settings to a working session previously as instructed here