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
Negative TIME/LTIME values are undefined.
Examples
ST
var1 := 7-2;
FBD
