FCM failed again tonight at UT=7:45, when attempting to do a Y observation. 

Following the guidelines from yesterday we tried to put in the block filter before restarting SISPI. It didn't work. FCM was restarted, then SISPI. Everything came back fine. We manually changed filters using the commands "set filter r", "set filter out". It worked fine for all filters except for Y.  After the second failure a simple Configure solved the interlock. Recalling the failure from a few months ago, we moved the telescope to the west, and tried again. Again, it failed when trying to move in the filter Y. This time, Configure did not work and SISPI was restarted. It was necessary anyway to do a reset_filter  after the SISPI restart to get things working again.

We were able to do a few observations before this failure, and it succesfully made ugrizY observations of three objects. It failed in the Y observations of the fourth object.

We continued observations with no Y. It went ok. At UT=9:37, I forgot to delete the Y observation in one of my targets and FCM failed again. Another SISPI restart and reset_filter.

Block filter has Y. So, I am leaving as a block u+z for tonight.