ABB FSO-12 User Manual page 60

60 Safety functions
Step Description
1 The STO request is received (for example, from the I/O). The FSO activates the SBC
function (brake) and starts counters for times A and B.
2 After time C has elapsed, the SBC starts to brake the motor.
3 After time A has elapsed, the FSO activates the drive STO.
4 After time B has elapsed, the FSO module defines the motor as stopped and the STO
completed indication goes on. The acknowledgement becomes allowed as soon as the
STO request has been removed (step 5).
5 The STO request is removed.
6 After the acknowledgement, the STO and SBC functions are deactivated, and the
control is given back to the drive, which controls the brake from now on. The
indications go off.