Date and time instructions
304
Part II IEC Instructions
SUB_TOD_TOD
Subtract Time of Day from Time of Day
To add an enable input and enable output to the instruction, select [With EN/ENO] from the
"Instructions" pane (LD, FBD or IL editor). To reuse an instruction select "Recently used" from the
context menu or press <Ctrl>+<Shift>+<v> in the programming window.
PLC types
Availability of SUB_TOD_TOD (see page 1331)
Data type I/O Function
TIME_OF_DAY 1st input minuend
TIME_OF_DAY 2nd input subtrahend
TIME output result
Description
SUB_TOD_TOD subtracts a value of the data type TIME_OF_DAY from another TIME_OF_DAY
value. The result is stored in the output variable of the data type TIME.
Data types
Example
In this example the function has been programmed in ladder diagram (LD) and structured text (ST).
POU header
All input and output variables used for programming this function have been declared in the POU
header.
LD
ST
When programming with structured text, enter the following:
TIME_result := SUB_TOD_TOD(TOD_value1, TOD_value2);