Found the spatial overlap on the Suna microscope with Zyla.
Found the SDL motor position giving 200 fs time difference between the upper and lower branches. 
The encoder and current values of DC2_CASZ and DC1_CASZ are not 100 % correlated. 
The SDL delay scan using ScanTool has an issue due to the incorrect motor movement. 
The manual delay scan has been attempted, which was not successful.