You perform clock and calendar functions in the U90 Ladder with Clock function blocks. These functions are on the Clock drop-down menu of the Ladder toolbar:
Time
Day of the Week
Day of the Month
Month
Year
U90 Ladder provides 2 methods for executing Clock functions:
You set the value of Direct Clock functions when you write your project.
The user sets the value of an Indirect Clock function from the PLC via the keypad.
To learn how to use Clock functions, check sample applications, such as the applications ' School Bell Direct', 'Database Log', and 'Print & Time'. To open these applications, select Sample U90 Projects from the Help Menu.