
Safe Torque Off
6-7
890CS Common Bus Supply - Frames B & D; 890CD Common Bus Drive and 890SD Standalone Drive - Frames E & F
Safety Specification
As assessed to EN ISO13849-1 and EN61800-5-2 and certified by BGIA (a German trade association for
industrial safety) the 890 frames B to F have the following related safety values:-
Criterion
Requirement
Value achieved
SIL3
For type A subsystems, HFT = 1:
SFF ≥ 60%
98%
SIL3
10
-7
≥ PFH ≥ 10
-8
1 x 10
-9
PLe
Category 3; PFH
≤
4,29 x 10
-8
1 x 10
-9
PLe
3
0 years ≤
MTTFd < 100 years
100 years
PLe
DC = medium
Medium
Mission Time
20 years
20 years
Note: all values quoted in this table are valid only when the two STO user inputs are driven independently. This
is as required by EN ISO 13849-1 category 3. See the Alignment to European Standards section in this chapter
for the required architecture which must be used throughout the machine design relevant to the drive under
consideration.
EMC Specification
In addition to the mandatory requirements of EN61800, the STO functionality has been subjected to testing for
immunity at higher levels. In particular it has been tested for radiated immunity up to 3GHz which includes
frequencies used by mobile telephones and walkie-talkies.
1
EN ISO13849 limits MTTFd to 100 years.