User Manual
Section 5
GFK-2958L
May 2021
Detailed Description of I/O Modules
222
5.16.10
Additional Counter Features
You can define the additional features for the counter listed below by parameterizing or via
the process data outputs:
•
Reset: resets the counting value to the load value during counting.
•
Latch function: stores the current counting value in the latch register.
•
Comparator: Upon meeting the comparison condition, the digital output is activated,
or a process alarm is triggered.
•
Hysteresis: reduces frequent switching of the output and/ or excessive triggering of
process alarms, e.g. when the value of a sensor signal fluctuates around the comparison
value. Figure 117 illustrates how counting behavior is affected by the additional
features. These additional features are explained in the following pages.
Figure 117: Additional Counter Functions
Reset
The load value will be load into the counting value once there is a signal at the reset input.
To use this feature, you must release the reset mode in the control word (bit QX8.0) in
addition to the parameterization.
The status bit IX8.3 indicates that there is a signal at the reset input. Once a reset is done,
the status bit IX8.0 is set. This bit will be reset by deactivating the reset mode (control bit
QX9.0).
Latch Function
If a 0-1 edge appears at the latch input during a counting process, the current counter value
is stored in the latch register. The latch register is accessed through the process data inputs.
With every activation of the counter the latch value is set to 0.
Comparison Function
