Operator: SUB

The IEC operator subtracts variables.

Permitted data types: BYTE, WORD, DWORD, LWORD, SINT, USINT, INT, UINT, DINT, UDINT, LINT, ULINT, REAL, LREAL, TIME, LTIME, TIME_OF_DAY (TOD), LTIME_OF_DAY (LTOD), DATE, LDATE, DATE_AND_TIME (DT) LDATE_AND_TIME (DT)

Possible combinations for time data types

TIME - TIME = TIME
LTIME - LTIME = LTIME

Possible combinations for date and time data types

DATE - DATE = TIME
LDATE - LDATE = LTIME
TOD - TIME = TOD
LTOD - LTIME = LTOD
TOD - TOD = TIME
LTOD - LTOD = LTIME
DT - TIME = DT
LDT - LTIME = LDT
DT - DT = TIME
LDT - LDT = LTIME

Tip

Negative TIME/LTIME values are undefined.

Example 108. Examples

var1 := 7-2;

FBD