Festo CP-E08-M8-CL - A.5 General Information on Parameterisation

A. Technical appendix
A−22
Festo P.BE−CPEA−CL−EN en 0711a
A.5 General information on parameterisation
You can parameterise the behaviour of the CPI modules (e.g.
diagnostic behaviour etc.). Access to the parameters depends
on the CPI master used:
 CPX−CP interface as CPI master: parameterisation via the
fieldbus or via the handheld (CPX−MMI).
 CPV Direct as CPI master: parameterisation via the field
bus.
The basics of the parameters Input debounce
time and Signal
extension are described in what follows. Further information
on parameterisation can be found in the CPX system manual.
A.5.1 Input debounce time (only with CP−EL modules)
Basics
Input debouncing times are specified in order to eliminate
interfering changes of signal edge during switching pro
cedures (bouncing of the input signal). For example, mechan
ical switches generate brief undesired signal edges during
switching procedures. The signal states which are thereby
produced can cause interference in the control sequence and
should therefore frequently
be suppressed.
Interfering, undesired signal edges can be suppressed by a
PLC program in the higher−order controller. Interference can
therefore be avoided. With the CPI system, undesired signal
edges can be suppressed simply by parameterisation.
Parameterisation in the CPI system
With the CPI system, the input debouncing time can be set
with an appropriate module parameter. The possible input
debouncing times therefore depend on the particular type of
module. Typical input debouncing times are: 0.1ms, 3 ms
(typical presetting), 10 ms and 20 ms.