Chapter 10
273
I/O modules
10.2 ON-OFF filter and OFF-ON filter
Several unintentional brief signal changes occur when opening or closing a
component fitted with contacts as the result of the bouncing of the contacts. As this
may influence the evaluation of the input, you can use the ON-OFF filter for falling
edges (i.e. transitions from High to Low) and the OFF-ON filter for rising edges (i.e.
transitions from Low to High) to eliminate this effect.
To activate or deactivate the ON-OFF filter or the OFF-ON filter either click
on the checkbox or on the 3D buttons on the right side.
If the ON-OFF filter or the OFF-ON filter is active, a signal change will be recognized
only if it is confirmed by three consecutive identical samples of the input with a sample
rate of 4 ms, meaning constant signal for at least the duration of the filter time chosen.
For this purpose the state of the input is evaluated at an interval of 4ms.
On WS0-XTIO and WS0-XTDI with firmware version ≤ 2.xx the filter time is not
adjustable, but is fixed at 8 ms.
Consider extended reaction times when using the input filters!
• Due to the modules’ internal sampling rate of 4 ms, the ON-OFF filter and the OFF-
ON filter extend the reaction time by at least 8 ms.
• If the signal is alternating within these initial 8 ms, the signal change can be
delayed for much longer, i.e. until a constant signal of at least 8 ms has been
detected.
For dual-channel elements with complementary evaluation the respective filter (ON-
OFF or OFF-ON) is always related to the leading channel. Filtering of the
complementary channel is active automatically.
10.3 Disabling the test pulses of XTIO outputs
It is possible to disable the test pulses on one or several outputs of WS0-XTIO
modules with firmware version V2.00.0 and higher.
Disabling the test pulses of any output reduces the safety parameters of all
outputs!
Disabling the test pulses of one or more outputs of a WS0-XTIO module will reduce
the safety parameters for all outputs Q1…Q4 of this module. Consider this to ensure
that your application conforms to an appropriate risk analysis and avoidance strategy!
For detailed information on the safety parameters see the user’s manuals (hardware).
How to disable the test pulses of a WS0-XTIO output:
Connect an output element to the WS0-XTIO module.
Right click the output element and select Edit... from the context menu.
Deactivate the option Enable test pulses of this output. The test pulses of this
output are switched off. A notice will be displayed in the hardware configuration area
under the respective WS0-XTIO module.
ATTENTION
Note
ATTENTION
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