Siemens SIMATIC ET 200AL Manual page 73

Counting
4.3 Examples of counting
Start and stop the counting process via the gate control (counting direction forward, configuration
method 2xCount)
The following section shows the behavior of the counter depending on the control input at
the parameterization "Behavior DI: Gate control in combination with "Behavior when a
counting limit is exceeded: Stop counting".
If you set the HW gate to "1" via the control input, the counting process is started. If you set
the HW gate to "0", the counting process stops.
Note that the counting process also stops if you close the SW gate while the HW gate is
opened.
HW gate ans SW gate together form the internal gate. The module only counts when the
internal gate is open.
The following figure shows an example of the behavior of the counter at gate control with the
principle of stopping counting when a counting limit is exceeded.
Figure 4-15
72
Gate control and principle: Stop counting
Digital input/Digital output module DIQ 16x24VDC/0.5A 8xM12 (6ES7143-5AH00-0BA0)
Manual, 03/2019, A5E38688112-AC