Siemens SIMATIC S7-300 FM 350-1 Manual page 123

Single Setting with DI Set
The following figure shows single setting of the counter with digital input DI Set. In the case
represented here, only ENSET_UP is set, i.e., the counter is set during up counting.
With the first rising pulse edge at digital input DI Set, the counter is set provided that
ENSET_UP is similarly set. If you want to set the counter again, you must first reset
ENSET_UP and then set it again. The next positive pulse edge at digital input DI Set will
then result in the counter being set.
Figure 7-23 Single Setting with DI Set
Multiple Setting with DI Set
The following figure shows multiple setting of the counter with DI Set. In the case
represented here, only ENSET_UP is set, i.e., the counter is set during up counting.
With every rising pulse edge at digital input DI Set, the counter is set provided that
ENSET_UP is similarly set. If you reset ENSET_UP, the counter will not be set by DI Set.
Only when you have set ENSET_UP again, will the next positive edge at DI Set result in the
setting of the counter.
Figure 7-24 Multiple Setting with DI Set
FM 350-1 Counter module
Manual, 05/2011, A5E03648639-01
Operating Modes, parameters and commands
7.3 Count modes
123