Lenze i550

12.6.6.9 STO (Safe Torque O)
The status of the STO acvity is included in bit 15 of the CiA 402 status word (0x6041
(P780.00)).
This status informaon is required since the acvaon of STO causes all integral control parts
to be deleted.
In case of hoists, for instance, the inverter would be sagging without any correcve measures
aer compleng STO.
In order to prevent this unwanted state, the control has to be preloaded with a starng value
aer compleng STO:
•
In case of a control type with encoder, the integral-acon component of the speed control-
ler must be preloaded.
•
In case of V/f characterisc control for asynchronous motor (VFC closed loop), the slip fre-
quency must be preloaded.
If STO is inhibited, a changeover to the "Ready to switch on" device state takes
place and a warning is output.
Conguring the network
Device prole CiA 402
Device states
327