F-Di Signal Filtering - Siemens SINAMICS G120 Function Manual

3.2.2

F-DI signal filtering

The inverter checks the consistency of the fail-safe digital input signals. Consistent signals at
both inputs always assume the same signal state (high or low).
Discrepancy
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 long-term discrepancy points toward a fault in the wiring of a
fail-safe input, e.g. a wire break.
An adjustable filter in the inverter prevents faults caused by temporary discrepancy. Within
the filter's tolerance time, the inverter suppresses the discrepancy monitoring of the fail-safe
inputs.
Figure 3-1
Table 3- 3
p9650, p9850
The filter does not increase 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.
The way in which the inverter responds to a discrepancy depends on the active safety
function. Further information can be found in the section Cause of fault (Page 190).
Safety Integrated Function Manual, SINAMICS G120 and G120C
Function Manual, 01/2011, FW 4.4, A5E03052391B AB
Filter for suppressing discrepancy monitoring
Parameters for the discrepancy monitoring tolerance time
Basic Safety
Activation via F-DI
p10002, p10102
3.2 Activation via F-DI
Extended Safety
Activation both via F-DI and
PROFIsafe
p9650, p9850
Interfaces
77