WAGO 8FDI 24V PROFIsafe 750-662/000-004 Manual page 65

WAGO I/O System
750-662/000-004 8FDI 24V PROFIsafe
You can use the value of the parameter to specify the maximum permissible time
for a deviation (invalid signal state) of the two input signal states of the valence
rule.
The F I/O module begins discrepancy monitoring as soon as a deviation of the
input signal states from the valence rule is detected.
Discrepancy time monitoring is terminated when a valid signal status is achieved
(0-signal or 1-signal; see section "Commissioning" > ... > "Pre-Evaluation
Parameter"), depending on the signal status that was present at the digital inputs
prior to the beginning of discrepancy monitoring.
You can set the discrepancy time for each channel pair separately in the value
range from 5 ... 65000 ms in 25 steps.
The discrepancy time must be greater than the sum of the test pulse duration and
input filter time.
Discrepancy Time Monitoring and Discrepancy Time
The discrepancy time monitoring feature checks whether there are unacceptable
delays between the signals of the two input channels. For example, this can be
used to detect mechanical or electro-mechanical deviations from the nominal
state of simultaneity.
Discrepancy time monitoring of the dual-channel pre-evaluation is used to
deduce the existence of sensor errors based on the chronological progression of
the signal states. Discrepancy time monitoring is activated if the signal states
deviate from the valence rule.
Discrepancy time monitoring activated only after the amount of time
corresponding to the Input Filter Time setting has elapsed
Discrepancy time monitoring not activated until the input filter time has elapsed.
During error-free operation, the input signals will take on acceptable signal states
within the discrepancy time period. Discrepancy time monitoring is started and
ends before the discrepancy time elapses.
Set the value of the Discrepancy Time parameter high enough that both digital
inputs can complete the change of signal voltage before the discrepancy time
has elapsed.
Behavior of the F I/O Module during Discrepancy Time Monitoring
If the process image of the F I/O module transfers a 1-signal due to the input
signal states, and a deviation of the input signal states from the valence rule is
then detected, discrepancy time monitoring starts. Discrepancy time monitoring is
not terminated until a 0-signal is detected.
Version 1.0.0, valid from HW/SW Version 01/01
Commissioning 65
Manual