Additional Functions Features - GE RSTi-EP User Manual

5.14.3 Additional Functions Features

You can define the additional features for the counter listed below by parameterising 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.The
figure illustrates how counting behavior is affected by the additional features. These
additional features are explained in the following pages.
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 have to 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.
GFK-2958E
Chapter 5 Detailed Descriptions of I/O Modules
Additional Counter Functions
RSTi-EP User Manual 175