VIPA System 300S SPEED7 CPU 313SC/DPM - Page 114

Chapter 5 Deployment I/O periphery Manual VIPA System 300S SPEED7
5-28 HB140E - CPU SC - RE_313-6CF03 - Rev. 07/45
The hysteresis serves e.g. the avoidance of many toggle processes of the
output and the interrupt, if the counter value is in the range of the
comparison value. You may set a range of 0 to 255. The settings 0 and 1
deactivate the hysteresis. The hysteresis influences the zero run, over- and
underflow.
An activated hysteresis remains active after a change. The new hysteresis
range is taken over at the next reach of the comparison value.
The following pictures illustrate the output behavior for hysteresis 0 and
hysteresis 3 for the according conditions:
Effect at counter value
≥ comparison value
8
7
6
5
4
3
2
1
0
Comparison value
Hysteresis
Output:
Hysteresis = 0
Hysteresis = 3
Counter value
1
2
3
4
5 6
7
1
Counter value ≥ comparison value → output is set and hysteresis activated
2
Leave hysteresis range → output is reset
3
Counter value ≥ comparison value → output is set and hysteresis activated
4
Leave hysteresis range, output remains set for counter value ≥ comparison value
5
Counter value < comparison value and hysteresis active → output is reset
6
Counter value ≥ comparison value → output is not set for hysteresis active
7
Leave hysteresis range, output remains set for counter value ≥ comparison value
With reaching the comparison condition the hysteresis gets active. At
active hysteresis the comparison result remains unchanged until the
counter value leaves the set hysteresis range. After leaving the hysteresis
range a new hysteresis is only activated with again reaching the
comparison conditions.
Hysteresis