Technical data

Appendix
27.8 Setting the Operating Behavior
Programming with STEP 7
684 Manual, 05/2010, A5E02789666-01
Note
If you use more timers in your user program than the CPU permits, a synchronous error is signaled and OB121
started.
On the S7-300 (with the exception of the CPU 318), timers can be started and updated simultaneously only in
OB1 and OB100; in all other OBs timers can only be started.