When using the 2 value display function, 3 step setting is not available for the display. 
(When setting 3 step, select each set value to be displayed by pressing the    or    button.) 
 
When output operation mode is changed after selecting the 2 value display, the selected display items will 
not be applicable and [- - -] will be displayed. In this case, select items for the 2 value display setting again.