WAGO -I/O-SYSTEM 750 Manual page 99

WAGO-I/O-SYSTEM 750
750-667/000-003 4FDI/4FDO 24V/2A PROFIsafe V2 iPar
• No equivalent (same) states are detected with equivalent valence rule
• No antivalent (opposing) states are detected with antivalent valence rule
Activate discrepancy time monitoring only after the set input filter time has
elapsed!
Discrepancy time monitoring is only activated if the input filter time has expired.
During error-free operation, the input signals will assume acceptable signal states
within the discrepancy time period. Discrepancy time monitoring is started and
also ends before the discrepancy time expires.
Set the value of the discrepancy time parameter such 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 is started. Discrepancy time
monitoring is not terminated until a 0-signal is detected.
If the process image of the F I/O module transfers a 0-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 is started. Discrepancy time
monitoring is not terminated until either a 0-signal or a 1-signal is detected.
As discrepancy time monitoring progresses in the F I/O module, the "0" value is
output from the affected input pair to the safe PLC as a safe process image.
Behavior of the F I/O module after expiration of the discrepancy time
If the invalid input signal status is detected by the F I/O module longer than the
configured discrepancy time, there is a discrepancy error, the F I/O module is
passivated and the "Discrepancy time exceeded" diagnostic message it output to
the safe PLC. The discrepancy error can be caused, for example, by a wire
discontinuity in a signal line, a sensor error, etc.
Behavior of the F I/O module during discrepancy time errors
If the a discrepancy error is detected by the F I/O module, all digital inputs and
power outputs are passivated by the F I/O module. Depending on the Restart
inhibit parameter setting, you can acknowledge the reported error(s) with or
without eliminating the cause of the error (see section "Parameter Restart Inhibit
Ix & Ix+1").
Version 1.4.2, valid from HW/SW Version 01/02
Commissioning 99
Manual