Siemens CU240B-2 - Page 338

Advanced commissioning
6.8 Safe Torque Off (STO) safety function
Converter with the CU240B-2 and CU240E-2 Control Units
338 Operating Instructions, 01/2016, FW V4.7 SP6, A5E34259001B AC
If the safety-related input signals too many signal changes within a certain time, then the
inverter responds with a fault.
Image 6-67 Inverter response to a bit pattern test
An adjustable signal filter in the inverter suppresses temporary signal changes using bit
pattern test or contact bounce.
The filter increases the inverter response time. The inverter only selects its safety function
after the debounce time has elapsed.
Image 6-68 Filter for suppressing temporary signal changes
Parameter
Description
p9650
F-DI changeover tolerance time
(factory setting: 500 ms)
Tolerance time to change over the fail-safe digital input for the basic functions.
p9651
STO debounce time
(factory setting: 1 ms)
Debounce time of the fail-safe digital input for the basic functions.