Hitachi Kokusai Electric KP-F520WCL Operation Manual page 33

Graph following shows frame rate in each of picture grabbing in the partial scan mode.
Note: Frame rate can be calculated from following equations using width of picture grabbing.
*Notes when partial scanning is used
Note1: Please use the partial scan in following condition.
Start + Width ≦ 2059
Note2: Please use FVAL in the partial scan.
KP-F520WCL Partial scan
Lines = 14 + Width + (2067 - Width) / 4
Frame rate = (72000000 / 1924) / Lines
Width [H]
25