HP 16550A User Reference page 195

The Chart Menu
Stop Measurement Field
Compare
When Compare is selected, a repetitive run is stopped when a comparison of
data in the Listing menu and data and criteria in a compare image matches an
equality selection. The equality selection is set from the Equal/Not Equal
selection pop-up menu.
Equal The data and compare criteria in the Compare menu must be
equal to the data in the Listing menu.
Not Equal The data and compare criteria in the Compare menu must
not be equal to the data in the Listing menu.
Compare field Equality selection menu
Equal / Not Equal Selection Menu
8–21