Siemens Simatic S7 Series

Program instructions
7.17 Timer
S7-200 SMART
344 System Manual, 09/2015, A5E03822230-AC
100 ms timer
Q0.0 is always turned ON for one scan whenever the timer’s current value reaches the
preset value.
7.17.3
Interval timers
LAD / FBD
STL
Description
BITIM OUT
The Begin interval time instruction reads the current value of the built-in 1 milli-
second counter and stores the value in OUT. The maximum timed interval for a
DWORD millisecond value is 2 raised to the 32 power or 49.7 days.
CITIM IN, OUT
The Calculate interval time instruction calculates the time difference between the
current time and the time provided at IN. The difference is stored in OUT. The
maximum timed interval for a DWORD millisecond value is 2 raised to the 32
power or 49.7 days. CITIM automatically handles the one millisecond timer rollo-
ver that occurs within the maximum interval, depending on when the BITIM in-
struction was executed.
Non-fatal errors with ENO = 0
SM bits affected
• 0006H Indirect address
None
Input / output
Data type
Operand
IN
DWORD
VD, ID, QD, MD, SMD, SD, LD, AC, *VD, *LD, *AC
OUT
DWORD
VD, ID, QD, MD, SMD, SD, LD, AC, *VD, *LD, *AC