Advanced commissioning
6.11 Safe Torque Off (STO) safety function
Converter with the control units CU240D-2
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Operating Instructions, 04/2018, FW V4.9 SP10, A5E34262100B AF
6.11.3.5
Setting the filter for fail-safe digital inputs
Requirement
You are online with Startdrive.
Procedure
1.
Navigate to the filter settings.
2.
Set the debounce time for the F-DI input filter.
3.
Set the discrepancy time for the simultaneity monitoring.
You have set the input filter and the simultaneity monitoring of the failsafe digital input.
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Description of the signal filter
The following filters are available for the fail-safe digital inputs:
●
One filter for the simultaneity monitoring
●
A filter to suppress short signals, e.g. test pulses.
Set the discrepancy time for the simultaneity monitoring.
The inverter checks that the two input signals of the fail-safe digital input always have the
same signal state (high or low).
With electromechanical sensors (e.g. emergency stop buttons or door switches), the two
sensor contacts never switch at exactly the same time and are therefore temporarily
inconsistent (discrepancy). A permanent discrepancy signifies a fault in the fail-safe digital
input circuit, e.g. wire breakage.
When appropriately set, the inverter tolerates brief discrepancies.
The discrepancy time does not extend the inverter response time. The inverter selects its
safety function as soon as one of the two F-DI signals changes its state from high to low.
