Interval Timers - Siemens SIMATIC S7 System Manual

Program instructions
7.17 Timer
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
BITIM OUT
CITIM IN, OUT
Non-fatal errors with ENO = 0
0006H Indirect address
•
Input / output Data type
IN DWORD
OUT DWORD
386
Description
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.
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.
SM bits affected
None
Operand
VD, ID, QD, MD, SMD, SD, LD, AC, *VD, *LD, *AC
VD, ID, QD, MD, SMD, SD, LD, AC, *VD, *LD, *AC
System Manual, V2.3, 07/2017, A5E03822230-AF
S7-200 SMART