Siemens SIMATIC S7-300 FM 350-1 Manual page 91

Selecting the Gate Function
You can select the gate control in this mode. The following possibilities are available to you:
● Without gate (default)
● SW gate
● Hardware gate, level-controlled or edge-controlled
Opening and Closing the Software Gate
You open and close the software gate of the counter in each case with the input parameter
SW_GATE of the FC CNT_CTL1.
Table 7- 6
Action
Open software gate
Close software gate
When the software gate opens, the counting operation resumes with the current counter
level.
Opening and Closing the Hardware Gate
You open and close the hardware gate by applying the relevant signals to or removing the
signals from the digital inputs DI Start and DI Stop.
Table 7- 7
Action
Open hardware gate (level-controlled)
Close hardware gate (level-controlled)
Open hardware gate (edge-controlled)
Close hardware gate (edge-controlled)
When the hardware gate opens, the counting operation resumes with the current counter
level.
FM 350-1 Counter module
Manual, 05/2011, A5E03648639-01
Figure 7-1 Continuous counting with gate control
Triggering the Opening/Closing of a SW Gate (Continuous Counting)
Triggering the Opening/Closing of a HW Gate (Continuous Counting)
Operating Modes, parameters and commands
...Is initiated by
Setting SW_GATE
Resetting SW_GATE
...Is initiated by
Apply signal to digital input DI Start
Remove signal from digital input DI Start
Apply positive pulse edge across digital input DI
Start
Apply positive pulse edge across digital input DI
Stop
7.3 Count modes
91