146 Safe torque off functionperformed and the drive trips. An attempt to use the STO in a non-redundant manner, forexample activating only one channel, will trigger the same reaction.See the drive firmware manual for the indications generated by the drive, and for details ondirecting fault and warning indications to an output on the control unit for externaldiagnostics.Any failures of the Safe torque off function must be reported to ABB.Safety data (SIL, PL)The safety data for the Safe torque off function is given below.* according to Table E.1 in EN/ISO 13849-1• This temperature profile is used in safety value calculations:• 670 on/off cycles per year with T = 71.66 °C• 1340 on/off cycles per year with T = 61.66 °C• 30 on/off cycles per year with T = 10.0 °C• 32 °C board temperature at 2.0% of time• 60 °C board temperature at 1.5% of time• 85 °C board temperature at 2.3% of time.• The safety data is calculated for redundant use, and does not apply if both channelsare not used.• The STO is a type A safety component as defined in IEC 61508-2.• Relevant failure modes:• The STO trips spuriously (safe failure)• The STO does not activate when requestedA fault exclusion on the failure mode “short circuit on printed circuit board” has beenmade (EN 13849-2, table D.5). The analysis is based on an assumption that onefailure occurs at one time. No accumulated failures have been analyzed.• STO reaction time (shortest detectable break): 1 ms• STO response time: 2 ms (typical), 5 ms (maximum)• Fault detection time: Channels in different states for longer than 200 ms• Fault reaction time: Fault detection time + 10 ms• STO fault indication (parameter 31.22) delay: < 500 ms• STO warning indication (parameter 31.22) delay: < 1000 msFrame SIL/SILCLSC PL SFF(%)PFH(T 1 = 20 a)(1/h)PFD(T 1 = 2 a)MTTF d(a)DC*(%)Cat. HFT CCF(%)Lifetime(a)U1 = 380…480 VR10, R11 3 3 e 99.88 1.05E-9 1.61E-6 12779 > 90 3 1 80 203AXD10000410558 REV B
